Publications

Abstract

n applied linguistics (AL), researchers have always been concerned with second language (L2) learners' knowledge of the target language (TL), investigating the development of TL grammar, vocabulary, and phonology, for instance.

Abstract

Although humans are the ultimate “natural language generators”, the area of psycholinguistic modeling has been somewhat underrepresented in recent approaches to Natural Language Generation in computer science. To draw attention to the area and illustrate its potential relevance to Natural Language Generation, I provide an overview of recent work on psycholinguistic modeling of language production together with some key empirical findings, state-of-the-art experimental techniques, and their historical roots. The techniques include analyses of speech-error corpora, chronometric analyses, eyetracking, and neuroimaging.
The overview is built around the issue of cognitive control in natural language generation, concentrating on the production of single words, which is an essential ingredient of the generation of larger utterances. Most of the work exploited the fact that human speakers are good but not perfect at resisting temptation, which has provided some critical clues about the nature of the underlying system.

Abstract

Relatively little work has examined the function of gaze in interaction. Previous research has mainly addressed issues such as next speaker selection (e.g. Lerner 2003) or engagement and disengagement in the conversation (Goodwin 1981). It has looked for gaze behavior in relation to the roles participants are enacting locally, (e.g., speaker or hearer) and in relation to the unit “turn” in the turn taking system (Goodwin 1980, 1981; Kendon 1967). In his seminal work Kendon (1967) claimed that “there is a very clear and quite consistent pattern, namely, that [the speaker] tends to look away as he begins a long utterance, and in many cases somewhat in advance of it; and that he looks up at his interlocutor as the end of the long utterance approaches, usually during the last phase, and he continues to look thereafter.” Goodwin (Goodwin 1980) introducing the listener into the picture proposed the following two rules: Rule1: A speaker should obtain the gaze of his recipient during the course of a turn of talk. Rule2: a recipient should be gazing at the speaker when the speaker is gazing at the hearer. Rossano’s work (2005) has suggested the possibility of a different level of order for gaze in interaction: the sequential level. In particular he found that gaze withdrawal after sustained mutual gaze tends to occur at sequence possible completion and if both participants withdraw the sequence is complete. By sequence here we refer to a unit that is structured around the notion of adjacency pair. The latter refers to two turns uttered by different speakers orderly organized (first part and second part) and pair type related (greeting-greeting, question-answer). These two turns are related by conditional relevance (Schegloff 1968) that is to say that the first part requires the production of the second and the absence of the latter is noticeable and accountable. Question-anwers are very typical examples of adjacency pairs. In this paper we compare the use of gaze in question-answer sequences in three different populations: Italians, speakers of Mayan Tzeltal (Mexico) and speakers of Yeli Ndye (Russel Island, Papua New Guinea). Relying mainly on dyadic interactions and ordinary conversation we will provide a comparison of the occurrence of gaze in each turn (to compare with the claims of Goodwin and Kendon) and we will describe whether gaze has any effect on the other participant response and whether it persists also during the answer. The three languages and cultures that will be compared here belong to three different continents and have been previously described as potentially following opposite rules: for speakers of Italian and Yeli Ndye unproblematic and preferred engagement of mutual gaze while for speakers of Tzeltal strong mutual gaze avoidance. This paper tries to provide an accurate description of their gaze behavior in this specific type of sequential conversation.

Abstract

One of the most conspicuous ways in which people distribute agency among each other is by asking another for help. Natural languages give people a range of forms to do this, the distinctions among which have consequences for how agency is distributed. Forms such as imperatives (e.g. ‘pass the salt’) and recurrent types of interrogatives (e.g. ‘can you pass the salt?’) designate another person as the doer of the action. In contrast to this, impersonal deontic statements (e.g. ‘it is necessary to get the salt’) express the need for an action without tying it to any particular individual. This can generate interactions in which the identity of the doer must be sorted out among participants, allowing us to observe the distribution of agency in vivo. The case of impersonal deontic statements demonstrates the importance of grammar as a resource for managing human action and sociality.

Abstract

The use of the imperative for requesting has been mostly explained on the basis of estimations of social distance, relative power, and entitlement. More recent research, however, has identified other selection factors to do with the functional and sequential relation of the action requested to the trajectory of the ongoing interaction. In everyday activities among family and friends, the imperative is typically warranted by an earlier commitment of the requestee to a joint project or shared goal which the action requested contributes to. The chapter argues this to be the primary use of the imperative for requesting in Italian informal interaction, and distinguishes it from other uses of the imperative that do not conform to the predominant pattern. These other uses are of two kinds: (i) secondary, that is, less frequent and formally marked imperatives that still orient to social-interactional conditions supporting an expectation of compliance, and (ii) deviant, where the imperative is selected in deliberate violation of the social-interactional conditions that normally support it, attracting special attention and accomplishing more than just requesting. This study extends prior findings on the functional distribution of imperative requests and makes a point of relating and classifying distinct uses of a same form of action, offering new insights into more general aspects of language use such as markedness and normativity.

Abstract

Human communication is often thought about in terms of transmitted messages in a conventional code like a language. But communication requires a specialized interactive intelligence. Senders have to be able to perform recipient design, while receivers need to be able to do intention recognition, knowing that recipient design has taken place. To study this interactive intelligence in the lab, we developed a new task that taps directly into the underlying abilities to communicate in the absence of a conventional code. We show that subjects are remarkably successful communicators under these conditions, especially when senders get feedback from receivers. Signaling is accomplished by the manner in which an instrumental action is performed, such that instrumentally dysfunctional components of an action are used to convey communicative intentions. The findings have important implications for the nature of the human communicative infrastructure, and the task opens up a line of experimentation on human communication.

Abstract

Listeners’ signals of recipiency, such as “Mm-hm” or “uh-huh” in English, are the most elementary or minimal “conversational turns” possible. Minimal, because apart from acknowledging recipiency and inviting the speaker to continue with his/her next turn, they do not add any new information to the discourse of the conversation. The goal of this project is to gather cross cultural information on listeners’ feedback behaviour during conversation. Listeners in a conversation usually provide short signals that indicate to the speaker that they are still “with the speaker”. These signals could be verbal (like for instance “mm hm” in English or “hm hm” in Dutch) or nonverbal (visual), like nodding. Often, these signals are produced in overlap with the speaker’s vocalisation. If listeners do not produce these signals, speakers often invite them explicitly (e.g. “are you still there?” in a telephone conversation). Our goal is to investigate what kind of signals are used by listeners of different languages to signal “recipiency” to the speaker.

Abstract

Little is known about cultural differences in interactional practices with infants. The goal of this task is to document the nature and emergence of caregiver-infant interaction/ communication in different cultures. There are two tasks: Task 1 – a brief documentation about the culture under investigation with respect to infant-caregiver interaction and parental beliefs. Task 2 – the “decorated room”, a task designed to elicit infant and caregiver.

Abstract

In the language Duna (Trans New Guinea), egophoric distributional patterns are a pervasive characteristic of verbal morphology, but do not comprise a single coherent system. Many morphemes, including evidential markers and future time inflections, show strong tendencies to co-occur with ‘informant’ subjects (the speaker in a declarative, the addressee in an interrogative), or alternatively with non-informant subjects. The person sensitivity of the Duna forms is observable in frequency, speaker judgments of sayability, and subject implicatures. Egophoric and non-egophoric distributional patterns are motivated by the individual semantics of the morphemes, their perspective-taking properties, and logical and/or conventionalised expectations of how people experience and talk about events. Distributional tendencies can also be flouted, providing a resource for speakers to convey attitudes towards their own knowledge and experiences, or the knowledge and experiences of others.

Abstract

Languages with egophoric systems require their users to pay special attention to who knows what in the speech situation, providing formal marking of whether the speaker or addressee has personal knowledge of the event being discussed. Such systems have only recently come to be studied in cross-linguistic perspective. This chapter has two aims in regard to contributing to our understanding of egophoric marking. Firstly, it presents relevant data from a relatively under-described and endangered language, Kaluli (aka Bosavi), spoken in Papua New Guinea. Unusually, Kaluli tense inflections appear to show a mix of both egophoric and first vs non-first person-marking features, as well as other contrasts that are broadly relevant to a typology of egophoricity, such as special constructions for the expression of involuntary experience. Secondly, the chapter makes a preliminary foray into issues concerning egophoric marking and child language, drawing on a naturalistic corpus of child-caregiver interactions. Questions for future investigation raised by the Kaluli data concern, for example, the potentially challenging nature of mastering inflections that are sensitive to both person and speech act type, the possible role of question-answer pairs in children’s acquisition of egophoric morphology, and whether there are special features of epistemic access and authority that relate particularly to child-adult interactions.

Abstract

The goal of this task is to investigate emotional categories across linguistic and cultural boundaries. There are three core tasks. In order to conduct this task you will need emotional vocalisation stimuli on your computer and you must translate the scenarios at the end of this entry into your local language.

Abstract

The present paper looks at semantic interference and gender congruency effects during bilingual picture-word naming. According to Costa, Miozzo & Caramazza (1999), only the activation from lexical nodes within a language is considered during lexical selection. If this is accurate, these findings should uphold with respect to semantic and gender/determiner effects even though the distractors are in another language. In the present study three effects were found, (1) a main effect of language, (2) semantic effects for both target language and non-target language distractors, and (3) gender congruency effects for targets with target-language distractors only. These findings are at odds with the language-specific proposal of Costa et al. (1999). Implications of these findings are discussed.

Abstract

This chapter describes neurolinguistic aspects of morphology, morphological theory, and especially morphological processing. It briefly mentions the main processing models in the literature and how they deal with morphological issues, i.e. full-listing models (all morphologically related words are listed separately in the lexicon and are processed individually), full-parsing or decompositional models (morphologically related words are not listed in the lexicon but are decomposed into their constituent morphemes, each of which is listed in the lexicon), and hybrid, so-called dual route, models (regular morphologically related words are decomposed, irregular words are listed). The chapter also summarizes some important findings from the literature that bear on neurolinguistic aspects of morphological processing, from both language comprehension and language production, taking into consideration neuropsychological patient studies as well as studies employing neuroimaging methods.

Abstract

Humans express emotional information in their facial expressions and body movements, as well as in their voice. In this chapter we consider the neural processing of a specific kind of vocal expressions, non-verbal emotional vocalizations e.g. laughs and sobs. We outline evidence, from patient studies and functional imaging studies, for both emotion specific and more general processing of emotional information in the voice. We relate these findings to evidence for both basic and dimensional accounts of the representations of emotion. We describe in detail an fMRI study of positive and negative non-verbal expressions of emotion, which revealed that prefrontal areas involved in the control of oro-facial movements were also sensitive to different kinds of vocal emotional information.

Abstract

The basic idea behind this task is to find out how languages encode basic shape distinctions such as dimensionality, axial geometry, relative size, etc. More specifically, we want to find out (i) which formal means are used cross linguistically to encode basic shape distinctions, and (ii) which are the semantic distinctions that are made in this domain. In languages with many shape-classifiers, these distinctions are encoded (at least partially) in classifiers. In other languages, positional verbs, descriptive modifiers, such as “flat”, “round”, or nouns such as “cube”, “ball”, etc. might be the preferred means. In this context, we also want to investigate what other “grammatical work” shapeencoding expressions possibly do in a given language, e.g. unitization of mass nouns, or anaphoric uses of shape-encoding classifiers, etc. This task further seeks to determine the role of shape-related parameters which underlie the design of objects in the semantics of the system under investigation.

Abstract

Kilivila, the Austronesian language of the Trobriand Islanders of Papua New Guinea, has a rich inventory of terms - nouns, verbs, adjectives and idiomatic phrases and expressions - to precisely refer to, and to differentiate emotions and inner feelings. This paper describes how the Trobriand Islanders of Papua New Guinea deal with the public display of emotions. Forms of emotion control in public encounters are discussed and explained on the basis of ritual communication which pervades the Trobrianders' verbal and non-verbal behaviour. Especially highlighted is the Trobrianders' metalinguistic concept of "biga sopa" with its important role for emotion control in encounters that may run the risk of escalating from argument and conflict to aggression and violence.

Abstract

This article provides a brief introduction into field research, its aims, its methods and the various phases of fieldwork.

Abstract

This paper reports on the results of my research on the lexical means Kilivila offers its speakers to refer to emotions and inner feelings. Data were elicited with 18 “Ekman’s faces” in which photos of the faces of one woman and two men illustrate the allegedly universal basic emotions (anger, disgust, fear, happiness, sadness, surprise) and with film stimuli staging standard emotions. The data are discussed on the basis of the following research questions: * How “effable” are they or do we observe ineffability – the difficulty of putting experiences into words – within the domain of emotions? * Do consultants agree with one another in how they name emotions? * Are facial expressions or situations better cues for labeling?

Abstract

Human ethologists have shown that humans are both attracted to others and at the same time fear them. They refer to this kind of fear with the technical term ‘social fear’ and claim that “it is alleviated with personal acquaintance but remains a principle characteristic of interpersonal behaviour. As a result, we maintain various degrees of greater distance between ourselves and others depending on the amount of confidence we have in the other” (Eibl-Eibesfeldt 1989: 335). The goal of this task is to conduct exploratory, heuristic research to establish a new subproject that – based on a corpus of video data – will investigate various forms of human spatial behaviour cross-culturally.

Abstract

This project aims to investigate how speakers of various languages in indigenous cultures verbally reason about moral issues. The ways in which a solution for a moral problem is found, phrased and justified will be taken as the basis for researching reasoning processes that manifest themselves verbally in the speakers’ arguments put forward to solve a number of moral problems which will be presented to them in the form of unfinished story plots or scenarios that ask for a solution. The plots chosen attempt to present common problems in human society and human behaviour. They should function to elicit moral discussion and/or moral arguments in groups of consultants of at least three persons.

Abstract

This chapter first compares data collected on Kilivila colour terms in 1983 with data collected in 2008. The Kilivila lexicon has changed from a typical stage IIIb into a stage VII colour term lexicon (Berlin and Kay 1969). The chapter then compares data on the Kilivila taste vocabulary collected in 1982/83 with data collected in 2008. No substantial change was found. Finally the chapter compares the 2008 results on taste terms with a paper on the taste vocabulary of the Torres Strait Islanders published in 1904 by Charles S. Myers. Kilivila provides evidence that traditional terms used for talking about colour and terms used to refer to tastes have remained relatively stable over time.

Abstract

This paper deals with the dramatic environmental, social and cultural changes on the Trobriand Islands which I experienced during 16 long- and short-term fieldtrips from 1982 to 2012. I first report on the climate change I experienced there over the years and provide a survey about the demographic changes on the Trobriand Islands – highlighting the situation in Tauwema, my village of residence on Kaile’una Island. Finally I report on the social and cultural impact these dramatic changes have for the Trobriand Islanders and their culture.

Abstract

This paper presents a project which tests the hypothesis of the universality of facial expressions of emotions crossculturally and crosslinguistically. First results are presented which contradict the hypothesis.

Abstract

Bronislaw Malinowski – based on his experience during his field research on the Trobriand Islands – pointed out that language is first and foremost a tool for creating social bonds. It is a mode of behavior and the meaning of an utterance is constituted by its pragmatic function. Malinowski’s ideas finally led to the formation of the subdiscipline “anthropological linguistics”. This paper presents three observations of the Trobrianders’ attitude to their language Kilivila and their language use in social interactions. They illustrate that whoever wants to successfully research the role of language, culture and cognition in social interaction must be on ‘common ground’ with the researched community.

Abstract

As I have already pointed out elsewhere (Senft 2008; 2010; 2014), the Gricean conversational maxims of Quality – “Try to make your contribution one that is true” – and Manner “Be perspicuous”, specifically “Avoid obscurity of expression” and “Avoid ambiguity” (Grice 1967; 1975; 1978) – are not observed by the Trobriand Islanders of Papua New Guinea, neither in forms of their ritualized communication nor in forms and ways of everyday conversation and other ordinary verbal interactions. The speakers of the Austronesian language Kilivila metalinguistically differentiate eight specific non-diatopical registers which I have called “situational-intentional” varieties. One of these varieties is called “biga sopa”. This label can be glossed as “joking or lying speech, indirect speech, speech which is not vouched for”. The biga sopa constitutes the default register of Trobriand discourse and conversation. This contribution to the workshop on philosophy and pragmatics presents the Trobriand Islanders’ indigenous typology of non-diatopical registers, especially elaborating on the concept of sopa, describing its features, discussing its functions and illustrating its use within Trobriand society. It will be shown that the Gricean maxims of quality and manner are irrelevant for and thus not observed by the speakers of Kilivila. On the basis of the presented findings the Gricean maxims and especially Grice’s claim that his theory of conversational implicature is “universal in application” is critically discussed from a general anthropological-linguistic point of view.

Abstract

It has been known at least since Abelard (12th century) that the classic Square of Opposition suffers from so-called undue existential import (UEI) in that this system of predicate logic collapses when the class denoted by the restrictor predicate is empty. It is usually thought that this mistake was made by Aristotle himself, but it has now become clear that this is not so: Aristotle did not have the Conversions but only one-way entailments, which ‘saves’ the Square. The error of UEI was introduced by his later commentators, especially Apuleius and Boethius. Abelard restored Aristotle’s original logic. After Abelard, some 14th- and 15th-century philosophers (mainly Buridan and Ockham) meant to save the Square by declaring the O-corner true when the restrictor class is empty. This ‘leaking O-corner analysis’, or LOCA, was taken up again around 1950 by some American philosopher-logicians, who now have a fairly large following. LOCA does indeed save the Square from logical disaster, but modern analysis shows that this makes it impossible to give a uniform semantic definition of the quantifiers, which thus become ambiguous—an intolerable state of affairs in logic. Klima (Ars Artium, Essays in Philosophical Semantics, Medieval and Modern, Institute of Philosophy, Hungarian Academy of Sciences, Budapest, 1988) and Parsons (in Zalta (ed.), The Stanford Encyclopedia of Philosophy, http://plato.standford.edu/entries/square/, 2006; Logica Univers. 2:3–11, 2008) have tried to circumvent this problem by introducing a ‘zero’ element into the ontology, standing for non-existing entities and yielding falsity when used for variable substitution. LOCA, both without and with the zero element, is critically discussed and rejected on internal logical and external ontological grounds.

Abstract

No idea is older in the history of linguistics than the thought that there is, somehow hidden underneath the surface of sentences, a form or a structure which provides a semantic analysis and lays bare their logical structure. In Plato’s Cratylus the theory was proposed, deriving from Heraclitus’ theory of explanatory underlying structure in physical nature, that words contain within themselves bits of syntactic structure giving their meanings. The Stoics held the same view and maintained moreover that every sentence has an underlying logical structure, which for them was the Aristotelian subject- predicate form. They even proposed transformational processes to derive the surface from the deep structure. The idea of a semantically analytic logical form underlying the sentences of every language kept reappearing in various guises at various times. Quite recently it re-emerged under the name of generative semantics.

Abstract

The task is designed to elicit vocabulary for simple sounds. The primary goal is to establish how people describe sound and what resources the language provides generally for encoding this domain. More specifically: (1) whether there is dedicated vocabulary for encoding simple sound contrasts and (2) how much consistency there is within a community in descriptions. This develops on materials used in The language of sound

Abstract

Traditional psycholinguistic studies take place in controlled experimental labs and typically involve testing undergraduate psychology or linguistics students. Investigating psycholinguistics in this manner calls into question the external validity of findings, that is, the extent to which research findings generalize across languages and cultures, as well as ecologically valid settings. Here we consider three ways in which psycholinguistics can be taken out of the lab. First, researchers can conduct cross-cultural fieldwork in diverse languages and cultures. Second, they can conduct online experiments or experiments in institutionalized public spaces (e.g., museums) to obtain large, diverse participant samples. And, third, researchers can perform studies in more ecologically valid settings, to increase the real-world generalizability of findings. By moving away from the traditional lab setting, psycholinguists can enrich their understanding of language use in all its rich and diverse contexts.

Abstract

Research on child language socialization has its roots in understanding the ways that adults and other caregivers interact with children in mundane social life and how these practices might enculturate the child into local communicative norms and ways of thinking ( Brown 1998 ; Clancy 1999 ; Danziger 1971 ; de León 1998 ; Garrett and Baquedano-López 2002 ; Heath 1983 ; Ochs and Schieffelin 1983, 1984 ). A second primary area of interest has been the effect of different socialization practices on more formal educational settings ( Heath 1983 ; Howard 2004 ; Michaels 1981 ; Moore 2006 , this volume; Philips 1983 ; Rogoff et al. 2003 ). However, as discussed in other contributions to this volume, language socialization extends into many other facets of life. Just as being a member of a cultural group or being a student requires socialization into the associated rights and obligations, so too does the role of medical patient or client. For instance, patients must understand how to explain their problems ( Halkowski 2006 ; Heritage and Robinson 2006 ); what information they should know about their bodies, their treatment, their life, and their medical history; and where to look during examinations ( Heath 1986 ), to name but a few of the norm-governed aspects of medical interaction. Physicians play an important role in a child's socialization into the patient role by providing

Abstract

When people request information, they have a variety of means for eliciting the information. In English two of the primary resources for eliciting information include asking questions, making statements about their interlocutor (thereby generating confirmation or revision). But within these types there are a variety of ways that these information elicitors can be designed. The goal of this task is to examine how different languages seek and provide information, the extent to which syntax vs prosodic resources are used (e.g., in questions), and the extent to which the design of information seeking actions and their responses display a structural preference to promote social solidarity.

Abstract

The current study examines, for the first time, the viewpoint preferences of signing children in expressing spatial relations that require imposing a viewpoint (left-right, front-behind). We elicited spatial descriptions from deaf children (4–9 years of age) acquiring Turkish Sign Language (TİD) natively from their deaf parents and from adult native signers of TİD. Adults produced these spatial descriptions from their own viewpoint and from that of their addressee depending on whether the objects were located on the lateral or the sagittal axis. TİD-acquiring children, on the other hand, described all spatial configurations from their own viewpoint. Differences were also found between children and adults in the type of linguistic devices and how they are used to express such spatial relations.

Abstract

The artificial grammar learning (AGL) paradigm enables systematic investigation of the acquisition of linguistically relevant structures. It is a paradigm of interest for language processing research, interfacing with theoretical linguistics, and for comparative research on language acquisition and evolution. This chapter presents a key for understanding major variants of the paradigm. An unbiased summary of neuroimaging findings of AGL is presented, using meta-analytic methods, pointing to the crucial involvement of the bilateral frontal operculum and regions in the right lateral hemisphere. Against a background of robust posterior temporal cortex involvement in processing complex syntax, the evidence for involvement of the posterior temporal cortex in AGL is reviewed. Infant AGL studies testing for neural substrates are reviewed, covering the acquisition of adjacent and non-adjacent dependencies as well as algebraic rules. The language acquisition data suggest that comparisons of learnability of complex grammars performed with adults may now also be possible with children.

Abstract

In this chapter, I review my EEG research on comprehending sentences in context from a pragmatics-oriented perspective. The review is organized around four questions: (1) When and how do extra-sentential factors such as the prior text, identity of the speaker, or value system of the comprehender affect the incremental sentence interpretation processes indexed by the so-called N400 component of the ERP? (2) When and how do people identify the referents for expressions such as “he” or “the review”, and how do referential processes interact with sense and syntax? (3) How directly pragmatic are the interpretation-relevant ERP effects reported here? (4) Do readers and listeners anticipate upcoming information? One important claim developed in the chapter is that the well-known N400 component, although often associated with ‘semantic integration’, only indirectly reflects the sense-making involved in structure-sensitive dynamic composition of the type studied in semantics and pragmatics. According to the multiple-cause intensified retrieval (MIR) account -- essentially an extension of the memory retrieval account proposed by Kutas and colleagues -- the amplitude of the word-elicited N400 reflects the computational resources used in retrieving the relatively invariant coded meaning stored in semantic long-term memory for, and made available by, the word at hand. Such retrieval becomes more resource-intensive when the coded meanings cued by this word do not match with expectations raised by the relevant interpretive context, but also when certain other relevance signals, such as strong affective connotation or a marked delivery, indicate the need for deeper processing. The most important consequence of this account is that pragmatic modulations of the N400 come about not because the N400 at hand directly reflects a rich compositional-semantic and/or Gricean analysis to make sense of the word’s coded meaning in this particular context, but simply because the semantic and pragmatic implications of the preceding words have already been computed, and now define a less or more helpful interpretive background within which to retrieve coded meaning for the critical word.

Abstract

This Field Manual entry has been superceded by the published version: Van Staden, M., & Majid, A. (2006). Body colouring task. Language Sciences, 28(2-3), 158-161. doi:10.1016/j.langsci.2005.11.004.

Abstract

Translated and expanded version of 'Privileged syntactic arguments, pivots and controllers

Abstract

The linguistic category of irrealis does not show stable semantics across languages. This makes it difficult to formulate general statements about this category, and it has led some researchers to reject irrealis as a cross-linguistically valid category. In this paper we look at the semantics of the irrealis category of Yurakaré, an unclassified language spoken in central Bolivia, and compare it to irrealis semantics of a number of other languages. Languages differ with respect to the subcategories they subsume under the heading of irrealis. The variable subcategories are future tense, imperatives, negatives, and habitual aspect. We argue that the cross-linguistic variation is not random, and can be stated in terms of an implicational scale.