Publications

Abstract

This paper examines some of the claims of the Unaccusativity hypothesis.It shows that the supposedly unaccusative ‘die’ verb in Ewe (Kwa), kú can appear as both a one-place and a two-place predicate and has three senses which do not correlate with the number of surface arguments of the verb. For instance, the same sense is involved in both a one-place construction (e.g. she died) and a two-place cognate object construction (she died a wicked death). By contrast, different senses are expressed by formally identical two-place constructions, e.g. ‘the garment die dirt’ (= the garment is dead dirty; intensity) vs., ‘he died ear (to the matter)’ (=he does not want to hear; negative desiderative). The paper explores the learnability problems posed by the non-predictability of the different senses of Ewe ‘die’ from its syntactic frame and suggests that since the meanings are indirectly related to the properties of the event participants, such as animacy, a learner must pay close attention to the properties of the verb’s participants. The paper concludes by demonstrating that the meaning shifts observed in Ewe are also attested in other typologically and genetically unrelated languages such as Japanese, Arrernte (Australian), Oluta (Mixean), Dutch and English.

Abstract

Lexical statistics and a production experiment are used to gauge the extent to which the linguistic notion of morphological productivity is relevant for psycholinguistic theories of speech production in languages such as Dutch and English. Lexical statistics of productivity show that despite the relatively poor morphology of Dutch, new words are created often enough for the marginalisation of word formation in theories of speech production to be theoretically unattractive. This conclusion is supported by the results of a production experiment in which subjects freely created hundreds of productive, but only a handful of unproductive, neologisms. A tentative solution is proposed as to why the opposite pattern has been observed in the speech of jargonaphasics.

Abstract

Language comprehension involves two basic operations: the retrieval of lexical information (such as phonologic, syntactic, and semantic information) from long-term memory, and the unification of this information into a coherent representation of the overall utterance. Neuroimaging studies using hemo¬dynamic measures such as PET and fMRI have provided detailed information on which areas of the brain are involved in these language-related memory and unification operations. However, much less is known about the dynamics of the brain's language network. This chapter presents a literature review of the oscillatory neuronal dynamics of EEG and MEG data that can be observed during language comprehen¬sion tasks. From a detailed review of this (rapidly growing) literature the following picture emerges: memory retrieval operations are mostly accompanied by increased neuronal synchronization in the theta frequency range (4-7 Hz). Unification operations, in contrast, induce high-frequency neuronal synchro¬nization in the beta (12-30 Hz) and gamma (above 30 Hz) frequency bands. A desynchronization in the (upper) alpha frequency band is found for those studies that use secondary tasks, and seems to correspond with attentional processes, and with the behavioral consequences of the language comprehension process. We conclude that it is possible to capture the dynamics of the brain's language network by a careful analysis of the event-related changes in power and coherence of EEG and MEG data in a wide range of frequencies, in combination with subtle experimental manipulations in a range of language comprehension tasks. It appears then that neuronal synchrony is a mechanism by which the brain integrates the different types of information about language (such as phonological, orthographic, semantic, and syntactic infor¬mation) represented in different brain areas.

Abstract

Landscape terms reflect the relationship between geographic reality and human cognition. Are ‘mountains’, ‘rivers, ‘lakes’ and the like universally recognised in languages as naturally salient objects to be named? The landscape subproject is concerned with the interrelation between language, cognition and geography. Specifically, it investigates issues relating to how landforms are categorised cross-linguistically as well as the characteristics of place naming.

Abstract

How do different languages and cultures conceptualise time? This question is part of a broader set of questions about how humans come to represent and reason about abstract entities – things we cannot see or touch. For example, how do we come to represent and reason about abstract domains like justice, ideas, kinship, morality, or politics? There are two aspects of this project: (1) Time arrangement tasks to assess the way people arrange time either as temporal progressions expressed in picture cards or done using small tokens or points in space. (2) A time & space language inventory to discover and document the linguistic coding of time and its relation to space, as well as the cultural knowledge structures related to time.

Abstract

(From the chapter) the first section considers very briefly the kinds of processes that can be inferred to underlie errors that do not set in until after a period of correct usage acquisition often seems to be a more extended process than we have envisioned summarize a currently influential model of how linguistic forms, meaning, and communication are interrelated in the acquisition of language, point out some challenging problems for this model, and suggest that the notion of "meaning" in language must be reconceptualized before we can hope to solve these problems evidence from several types of late errors is marshalled in support of these arguments (From the preface) provides many examples of new errors that children introduce at relatively advanced stages of mastery of semantics and syntax Bowerman views these seemingly backwards steps as indications of definite steps forward by the child achieving reflective, flexible and integrated systems of semantics and syntax (

Abstract

This chapter outlines two influential "bootstrapping" proposals that draw on presumed universals of argument structure to account for young children's acquisition of grammar (semantic bootstrapping) and verb meaning (syntactic bootstrapping), discusses controversial issues raised by these proposals, and summarizes the new insights contributed to the debate by each of the chapters in this volume.

Abstract

Attempts to explain children's grammatical development often assume a close initial match between units of meaning and units of form; for example, agents are said to map to sentence-subjects and actions to verbs. The meanings themselves, according to this view, are not influenced by language, but reflect children's universal non-linguistic way of understanding the world. This paper argues that, contrary to this position, meaning as it is expressed in children's early sentences is, from the beginning, organized on the basis of experience with the grammar and lexicon of a particular language. As a case in point, children learning English and Korean are shown to express meanings having to do with directed motion according to language-specific principles of semantic and grammatical structuring from the earliest stages of word combination.

Abstract

How similar are the event concepts encoded by different languages? So far, few event domains have been investigated in any detail. The PUT project extends the systematic cross-linguistic exploration of event categorisation to a new domain, that of placement events (putting things in places and removing them from places). The goal of this task is to explore cross-linguistic universality and variability in the semantic categorisation of placement events (e.g., ‘putting a cup on the table’).

Abstract

How are events framed in narrative? Speakers of English (a 'satellite-framed' language), when 'reading' Mercer Mayer's wordless picture book 'Frog, Where Are You?', find the story self-evident: a boy has a dog and a pet frog; the frog escapes and runs away; the boy and dog look for it across hill and dale, through woods and over a cliff, until they find it and return home with a baby frog child of the original pet frog. In Tzeltal, as spoken in a Mayan community in southern Mexico, the story is somewhat different, because the language structures event descriptions differently. Tzeltal is in part a 'verb-framed' language with a set of Path-encoding motion verbs, so that the bare bones of the Frog story can consist of verbs translating as 'go'/'pass by'/'ascend'/ 'descend'/ 'arrive'/'return'. But Tzeltal also has satellite-framing adverbials, grammaticized from the same set of motion verbs, which encode the direction of motion or the orientation of static arrays. Furthermore, motion is not generally encoded barebones, but vivid pictorial detail is provided by positional verbs which can describe the position of the Figure as an outcome of a motion event; motion and stasis are thereby combined in a single event description. (For example: jipot jawal "he has been thrown (by the deer) lying¬_face_upwards_spread-eagled". This paper compares the use of these three linguistic resources in frog narratives from 14 Tzeltal adults and 21 children, looks at their development in the narratives of children between the ages of 4-12, and considers the results in relation to those from Berman and Slobin's (1996) comparative study of adult and child Frog stories.

Abstract

How do children learn a language whose arguments are freely ellipsed? The Mayan language Tzeltal, spoken in southern Mexico, is such a language. The acquisition pattern for Tzeltal is distinctive, in at least two ways: verbs predominate even in children’s very early production vocabulary, and these verbs are often very specific in meaning. This runs counter to the patterns found in most Indo-European languages, where nouns tend to predominate in early vocabulary and children’s first verbs tend to be ‘light’ or semantically general. Here I explore the idea that noun ellipsis and ‘heavy’ verbs are related: the ‘heavy’ verbs restrict the nominal reference and so allow recovery of the ‘missing’ nouns. Using data drawn from videotaped interaction of four Tzeltal children and their caregivers, I examined transitive clauses in an adult input sample and in child speech, and tested the hypothesis that direct object arguments are less likely to be realized overtly with semantically specific verbs than with general verbs. This hypothesis was confirmed, both for the adult input and for the speech of the children (aged 3;4-3;9). It is therefore possible that argument ellipsis could provide a clue to verb semantics (specific vs. general) for the Tzeltal child.

Abstract

The surge of research activity focussing on children's acquisition of verbs (e.g., Tomasello and Merriman 1996) addresses some fundamental questions: Just how variable across languages, and across individual children, is the process of verb learning? How specific are arguments to particular verbs in early child language? How does the grammatical category 'Verb' develop? The position of Universal Grammar, that a verb category is early, contrasts with that of Tomasello (1992), Pine and Lieven and their colleagues (1996, in press), and many others, that children develop a verb category slowly, gradually building up subcategorizations of verbs around pragmatic, syntactic, and semantic properties of the language they are exposed to. On this latter view, one would expect the language which the child is learning, the cultural milieu and the nature of the interactions in which the child is engaged, to influence the process of acquiring verb argument structures. This paper explores these issues by examining the development of argument representation in the Mayan language Tzeltal, in both its lexical and verbal cross-referencing forms, and analyzing the semantic and pragmatic factors influencing the form argument representation takes. Certain facts about Tzeltal (the ergative/ absolutive marking, the semantic specificity of transitive and positional verbs) are proposed to affect the representation of arguments. The first 500 multimorpheme combinations of 3 children (aged between 1;8 and 2;4) are examined. It is argued that there is no evidence of semantically light 'pathbreaking' verbs (Ninio 1996) leading the way into word combinations. There is early productivity of cross-referencing affixes marking A, S, and O arguments (although there are systematic omissions). The paper assesses the respective contributions of three kinds of factors to these results - structural (regular morphology), semantic (verb specificity) and pragmatic (the nature of Tzeltal conversational interaction).

Abstract

This is an appropriate moment to review the state of the art in cognitive anthropology, construed broadly as the comparative study of human cognition in its linguistic and cultural context. In reaction to the dominance of universalism in the 1970s and '80s, there have recently been a number of reappraisals of the relation between language and cognition, and the field of cognitive anthropology is flourishing in several new directions in both America and Europe. This is partly due to a renewal and re-evaluation of approaches to the question of linguistic relativity associated with Whorf, and partly to the inspiration of modern developments in cognitive science. This review briefly sketches the history of cognitive anthropology and surveys current research on both sides of the Atlantic. The focus is on assessing current directions, considering in particular, by way of illustration, recent work in cultural models and on spatial language and cognition. The review concludes with an assessment of how cognitive anthropology could contribute directly both to the broader project of cognitive science and to the anthropological study of how cultural ideas and practices relate to structures and processes of human cognition.

Abstract

This paper surveys the lexical and grammatical resources for talking about spatial relations in the Mayan language Tzeltal - for describing where things are located, where they are moving, and how they are distributed in space. Six basic sets of spatial vocabulary are presented: i. existential locative expressions with ay ‘exist’, ii. deictics (demonstratives, adverbs, presentationals), iii. dispositional adjectives, often in combination with (iv) and (v), iv. body part relational noun locatives, v. absolute (‘cardinal’) directions, and vi. motion verbs, directionals and auxiliaries. The first two are used in minimal locative descriptions, while the others constitute the core resources for specifying in detail the location, disposition, orientation, or motion of a Figure in relation to a Ground. We find that Tzeltal displays a relative de-emphasis on deixis and left/right asymmetry, and a detailed attention to the spatial properties of objects.

Abstract

This is a reprint of the Brown and Levinson 2000 article.

Abstract

The systematic study of kinesics, gaze, and gestural aspects of communication in Central American cultures is a recent phenomenon, most of it focussing on the Mayan cultures of southern Mexico, Guatemala, and Belize. This article surveys ethnographic observations and research reports on bodily aspects of speaking in three domains: gaze and kinesics in social interaction, indexical pointing in adult and caregiver-child interactions, and co-speech gestures associated with “absolute” (geographically-based) systems of spatial reference. In addition, it reports how the indigenous co-speech gesture repertoire has provided the basis for developing village sign languages in the region. It is argued that studies of the embodied aspects of speech in the Mayan areas of Mexico and Central America have contributed to the typology of gestures and of spatial frames of reference. They have refined our understanding of how spatial frames of reference are invoked, communicated, and switched in conversational interaction and of the importance of co-speech gestures in understanding language use, language acquisition, and the transmission of culture-specific cognitive styles.

Abstract

This task has two parts: (i) video-taped elicitation of the range of possibilities for referring to persons and places, and (ii) observations of (first) references to persons and places in video-taped natural interaction. The goal of this task is to establish the repertoires of referential terms (and other practices) used for referring to persons and to places in particular languages and cultures, and provide examples of situated use of these kinds of referential practices in natural conversation. This data will form the basis for cross-language comparison, and for formulating hypotheses about general principles underlying the deployment of such referential terms in natural language usage.

Abstract

Interaction, for all that it has an ethological base, is culturally constituted, and how new social members are enculturated into the interactional practices of the society is of critical interest to our understanding of interaction – how much is learned, how variable is it across cultures – as well as to our understanding of the role of culture in children’s social-cognitive development. The goal of this task is to document the nature of caregiver infant interaction in different cultures, especially during the critical age of 9-15 months when children come to have an understanding of others’ intentions. This is of interest to all students of interaction; it does not require specialist knowledge of children.

Abstract

This article is a reprint of chapter 1, the introduction to Brown and Levinson, 1987, Politeness: Some universals in language usage (Cambridge University Press).

Abstract

This paper addresses the theories of Eve Clark about how children learn word meanings in western middle-class interactional contexts by examining child language data from a Tzeltal Maya society in southern Mexico where interaction patterns are radically different. Through examples of caregiver interactions with children 12-30 months old, I ask what lessons we can learn from how the details of these interactions unfold in this non-child-centered cultural context, and specifically, what aspects of the Tzeltal linguistic and interactional context might help to focus children’s attention on the meanings and the conventional forms of words being used around them.

Abstract

This special issue is the outcome of collaborative work on the relationship between language and landscape, carried out in the Language and Cognition Group at the Max Planck Institute for Psycholinguistics. The contributions explore the linguistic categories of landscape terms and place names in nine genetically, typologically and geographically diverse languages, drawing on data from first-hand fieldwork. The present introductory article lays out the reasons why the domain of landscape is of central interest to the language sciences and beyond, and it outlines some of the major patterns that emerge from the cross-linguistic comparison which the papers invite. The data point to considerable variation within and across languages in how systems of landscape terms and place names are ontologised. This has important implications for practical applications from international law to modern navigation systems.

Abstract

This paper investigates the integration of definite determiner phrases (DPs) as a function of their contextual salience, which is reflected in the degree of dependency on prior information. DPs depend on previously established discourse referents or introduce a new, independent discourse referent. This paper presents a formal model that explains how discourse referents are represented in the language system and what kind of mechanisms are implemented during DP interpretation. Experimental data from an event-related potential study are discussed that demonstrate how definite DPs are integrated in real-time processing. The data provide evidence for two distinct mechanisms – Specify R and Establish Independent File Card – and substantiate a model that includes various processes and constraints at the level of discourse representation.

Abstract

The idea that language shapes the way we think, often associated with Benjamin Whorf, has long been decried as not only wrong but also fundamentally wrong-headed. Yet, experimental evidence has reopened debate about the extent to which language influences nonlinguistic cognition, particularly in the domain of time. In this article, I will first analyze an influential argument against the Whorfian hypothesis and show that its anti-Whorfian conclusion is in part an artifact of conflating two distinct questions: Do we think in language? and Does language shape thought? Next, I will discuss crosslinguistic differences in spatial metaphors for time and describe experiments that demonstrate corresponding differences in nonlinguistic mental representations. Finally, I will sketch a simple learning mechanism by which some linguistic relativity effects appear to arise. Although people may not think in language, speakers of different languages develop distinctive conceptual repertoires as a consequence of ordinary and presumably universal neural and cognitive processes.

Abstract

A key part of learning to speak with others is figuring out when to start talking and how to hold the floor in conversation. For young children, the challenge of planning a linguistic response can slow down their response latencies, making misunderstanding, repair, and loss of the floor more likely. Like adults, children can mitigate their delays by using fillers (e.g., uh and um) at the start of their turns. In this chapter I analyze the onset and development of fillers in five children’s spontaneous speech from ages 1;6–3;6. My findings suggest that children start using fillers by 2;0, and use them to effectively mitigate delay in making a response.

Abstract

Conversation is a structured, joint action for which children need to learn a specialized set skills and conventions. Because conversation is a primary source of linguistic input, we can better grasp how children become active agents in their own linguistic development by studying their acquisition of conversational skills. In this chapter I review research on children’s turn-taking. This fundamental skill of human interaction allows children to gain feedback, make clarifications, and test hypotheses at every stage of development. I broadly review children’s conversational experiences, the types of turn-based contingency they must acquire, how they ask and answer questions, and when they manage to make timely responses

Abstract

Sentence production is the process we use to create language-specific sentences that convey particular meanings. In production, there are complex interactions between meaning, words, and syntax at different points in sentences. Computational models can make these interactions explicit and connectionist learning algorithms have been useful for building such models. Connectionist models use domaingeneral mechanisms to learn internal representations and these mechanisms can also explain evidence of long-term syntactic adaptation in adult speakers. This paper will review work showing that these models can generalize words in novel ways and learn typologically-different languages like English and Japanese. It will also present modeling work which shows that connectionist learning algorithms can account for complex sentence production in children and adult production phenomena like structural priming, heavy NP shift, and conceptual/lexical accessibility.

Abstract

Rudolf Meringer (1859–1931), Indo-European philologist, published two collections of slips of the tongue, annotated and interpreted. From 1909, he was the founding editor of the cultural morphology movement's journal Wörter und Sachen. Meringer was the first to note the linguistic significance of speech errors, and his interpretations have stood the test of time. This work, rather than his mainstream philological research, has proven his most lasting linguistic contribution

Abstract

The retiring academic may look back upon, inter alia, years of conference attendance. Speech error researchers are uniquely fortunate because they can collect data in any situation involving communication; accordingly, the retiring speech error researcher will have collected data at those conferences. We here address the issue of whether error data collected in situations involving conviviality (such as at conferences) is representative of error data in general. Our approach involved a comparison, across three levels of linguistic processing, between a specially constructed Conviviality Sample and the largest existing source of speech error data, the newly available Fromkin Speech Error Database. The results indicate that there are grounds for regarding the data in the Conviviality Sample as a better than average reflection of the true population of all errors committed. These findings encourage us to recommend further data collection in collaboration with like-minded colleagues.

Abstract

The lexicon, considered as a component of the process of recognizing speech, is a device that accepts a sound image as input and outputs meaning. Lexical access is the process of formulating an appropriate input and mapping it onto an entry in the lexicon's store of sound images matched with their meanings. This chapter addresses the problems of auditory lexical access from continuous speech. The central argument to be proposed is that utterance prosody plays a crucial role in the access process. Continuous listening faces problems that are not present in visual recognition (reading) or in noncontinuous recognition (understanding isolated words). Aspects of utterance prosody offer a solution to these particular problems.

Abstract

Speech signals originate as a sequence of linguistic units selected by speakers, but these units are necessarily realised in the suprasegmental dimensions of time, frequency and amplitude. For this reason prosodic structure has been viewed as a mandatory target of language processing by both speakers and listeners. In apparent contradiction, however, prosody has also been argued to be ancillary rather than core linguistic structure, making processing of prosodic structure essentially optional. In the present tribute to one of the luminaries of prosodic research for the past quarter century, we review evidence from studies of the processing of lexical stress and focal accent which reconciles these views and shows that both claims are, each in their own way, fully true.

Abstract

This article surveys what is currently known about the complex interplay between genetics and the language sciences. It focuses not only on the genetic architecture of language and speech, but also on their interactions on the cultural and evolutionary timescales. Given the complexity of these issues and their current state of flux and high dynamism, this article surveys the main findings and topics of interest while also briefly introducing the main relevant methods, thus allowing the interested reader to fully appreciate and understand them in their proper context. Of course, not all the relevant publications and resources are mentioned, but this article aims to select the most relevant, promising, or accessible for nonspecialists.

Abstract

Empirical studies addressing the age factor in second language acquisition have mainly been concerned with a comparison of end state data (from learners before and after the closure of a putative Critical Period for language acquisition) to the native speaker norm. Based on longitudinal corpus data, this paper investigates the affect of age on end state, rate and the process of acquisition and addresses the question of whether different grammatical domains are equally affected. To this end, the paper presents summarized findings from the acquisition of word order and inflectional morphology in L2 German by Russian learners of different ages and discusses theoretical implications that can be drawn from this evidence.

Abstract

This entry provides some orientation and task suggestions on how to explore the perceptual world of your field site and the interaction between the cultural world and the sensory lexicon in your community. The material consists of procedural texts; soundscapes; other documentary and observational tasks. The goal of this task is to explore the perceptual world of your field site and the interaction between the cultural world and the sensory lexicon in your community.

Abstract

Der vorliegende Beitrag zum Kieler Symposium1 stellt die Resultate eines Teilbereichs meiner Arbeit zum Guarani vor, nämlich einen Vorschlag zur Analyse der Personenpräfixe dieser Sprache und der mit ihnen verbundenen grammatischen Kategorien. Die im Titel angedeutete lexikographische Fragestellung bedarf einer näheren Erläuterung, die ich im Zusammenhang mit einer kurzen Darstellung der Motivation für meine Untersuchungen geben will

Abstract

With the present essay I pursue a threefold aim as will be explained in the following paragraphs. Since I cannot expect my readers to be familiar with the language studied, Guaran´ı, more information about this language will be given in the next subsection.

Abstract

Conclusion In this study we have examined the evidence for the exact genetic position of the Awetí language in the large Tupí family, especially evidence for an internal classification of the larger branch of Tupí called “Mawetí-Guaraní” which comprises the Tupí-Guaraní family, Awetí and Sateré-Mawé. As it turns out, we did not find any clear example of an uncommon sound change which would have happened after the separation of the antecessor of one branch but before the split between the other two. There is some just probability that Awetí belongs somewhat closer to Tupí-Guaraní within Mawetí-Guaraní (configuration A in Table 1), but we did not find any conclusive evidence. All we have are some weak indications the majority of which, however, point in this direction: • a higher number of cognates found between Awetí and proto-Tupí-Guarani; • lexicostatistic results (number of cognates in a 100-item-word-list proposed by Swadesh); • loss of long vowels in Awetí and Tupí-Guaraní, but not in Sateré-Mawé; • some sound changes suggest that in the development to Awetí and to proto-Tupí-Guaraní velar segments changes to dental segments (cf. the discussion of the correspondence set j : t : w); • possibly some of the correspondence sets given in Table 20. We consider it to be too soon to conclude that there is a branch Awetí + Tupí-Guaraní of Mawetí-Guaraní, opposed to Sateré-Mawé, but if there is any grouping, this hypothesis is most promising. 29

Abstract

This paper describes the verbal Tense-Aspect-Mood system of Awetí (Tupian, Central Brazil) in a Word-and-Paradigm approach. One classification of Awetí verb forms contains clear aspect categories. A second set of independent classifications renders at least four moods and contains a third major TAM classification, factuality, that has one mainly temporal category Future, while others are partially or wholly modal. Structural categories reflect the formal composition of the forms. Some forms are synthetic, ‘marked’ only by means of affixes, but many are analytic, containing auxiliary particles. With selected sample forms we demonstrate in detail the interplay of structural and functional categories in Awetí verb paradigms.

Abstract

The Pioneers project seeks to uncover relationships between the Papuan languages of Island Melanesia. One basic way to uncover linguistic relationships, either contact or genetic, is through lexical comparison. We have seen very few shared words between our Papuan languages and any other languages, either Oceanic or Papuan, but most of the words which are shared are shared because they are commonly borrowed from Oceanic languages. This task is aimed at enabling fieldworkers to collect terms for inland bird and tree species. In the past it is has proved very difficult for non-experts to identify plant and bird species, so the task consists of a booklet of colour pictures of some of the more common species, with information on the range and habits of each species, as well as some information on their cultural uses, which should enable better identification. It is intended that fieldworkers will show this book to consultants and use it as an elicitation aid.

Abstract

This Field Manual entry has been superceded by the 2007 version:
https://doi.org/10.17617/2.468728

Abstract

This field guide is for eliciting information about grammatical resources used in describing perceptual events and perception-based properties and states. A list of leading questions outlines an underlying semantic space for events/states of perception, against which language-specific constructions may be defined. It should be used as an entry point into a flexible exploration of the structures and constraints which are specific to the language you are working on. The goal is to provide a cross-linguistically comparable description of the constructions of a language used in describing perceptual events and states. The core focus is to discover any sensory asymmetries, i.e., ways in which different sensory modalities are treated differently with respect to these constructions.

Abstract

Laos features a high level of linguistic diversity, with more than 70 languages from four different major language families (Tai, Mon-Khmer, Hmong-Mien, Tibeto-Burman). Mon-Khmer languages were spoken in Laos earlier than other languages, with incoming migrations by Tai speakers (c. 2000 years ago) and Hmong-Mien speakers (c. 200 years ago). There is widespread language contact and multilingualism in upland minority communities, while lowland-dwelling Lao speakers are largely monolingual. Lao is the official national language. Most minority languages are endangered, with a few exceptions (notably Hmong and Kmhmu). There has been relatively little linguistic research on languages of Laos, due to problems of both infrastructure and administration.