If you have spent time with young children, you’ve probably heard them say things like “I go-ed to the park” or “She swimmed really fast.” These little slip-ups are part of how kids learn to talk—but they also reveal something deeper about how our brains build language.
When children learn a language with irregular forms, it's common to hear them make mistakes. For example, in English, a child might say go-ed instead of went, and in Dutch, helpte instead of hielp. What’s happening here? They’re trying to follow a regular pattern they’ve picked up: in English, you often make the past tense by adding “-ed” (like walk → walked or jump → jumped), and in Dutch, by adding -te or -de (like maak → maakte, leef → leefde). So when a verb doesn’t follow that pattern—like go → went or helpen → hielp—children sometimes get it “wrong” by applying the regular rule anyway. But these mistakes show us something important: they’re learning by trying to find patterns.
At first glance, it might seem like they’re just guessing. But researchers have been studying these errors for decades, and the truth is far more fascinating. These "mistakes" are actually clues—clues that tell us how children are piecing together the rules and patterns of their language.
Two Competing Theories
Some scientists believe kids use two systems: one for regular verbs (like “talked”) and another for irregular ones (“went,” “ran,” “sang”). This is called the dual-route theory—like having two mental pathways depending on the kind of verb. Others think children learn by storing lots of examples they hear—like walked, jumped, and played—and noticing patterns. They might realize that adding -ed usually makes a verb past tense. So when they come across a verb like help, they apply the same pattern and say helped—which is correct! But then they try the same for go, and say go-ed, not realizing yet that go is an exception. Over time, as they hear the correct form went more often, they start to figure out that go doesn't follow the usual pattern. This is the single-route or exemplar-based view.
But no matter which theory you support, almost everyone agrees: irregular verbs have to be learned, and some verbs are harder to learn than others.
So, why are some verbs more difficult?
The Puzzle of Verb Difficulty
To understand why some verbs are harder for children to learn than others, researchers have examined several properties of verbs that might play a role. One is how frequently a verb occurs in everyday language—went, for example, is much more common than arose, which may help explain why children tend to learn it earlier. Another property is phonological similarity: are there other verbs that sound similar and could influence how a child guesses the past tense? For instance, if a child hears that the past tense of melken (“to milk”) is molk, they might incorrectly apply the same pattern to helpen (“to help”), producing holp instead of hielp.
Researchers have also investigated whether the meaning of a verb affects how easily it is learned—specifically, whether the verb describes a completed action or a continuing state. Broke refers to an action with a clear endpoint: once something is broken, the event is over. In contrast, knew describes a state that can last indefinitely, with no clear boundary. This difference may influence how children mentally categorize verbs and apply grammatical rules.
Sounds like a solid plan, right?
Here’s the catch: most studies have used tiny datasets—just a handful of children or a few verbs. And they’ve mostly focused on English. That makes it hard to know what’s really going on. If children only make a few mistakes, there’s not enough to study for scientists. And if we only study English, we miss how this process plays out in languages with trickier verb systems.
A Bigger Picture
To truly understand how kids master past tense—especially the irregulars—we need to step back and ask broader questions. What happens in other languages? What if we had a larger, more detailed look at children’s actual learning patterns? Could we finally predict which verbs kids will struggle with, and why?
These are the questions driving a new wave of research into how children learn to talk about the past—not just in English, but in languages around the world. Join us in the next post in this series to learn more about how children learn Dutch.
Because when a child says “go-ed,” they’re not getting it wrong. They’re showing us, step by step, how language is learned.
Bibliography:
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3. Engelmann, F., Granlund, S., Kolak, J., Szreder, M., Ambridge, B., Pine, J., Theakston, A., & Lieven, E. (2019). How the input shapes the acquisition of verb morphology: Elicited production and computational modelling in two highly inflected languages. Cognitive Psychology, 110, 30–69. https://doi.org/10.1016/j.cogpsych.2019.02.001
4. Jeschull, L. (2007). The pragmatics of telicity and what children make of it. In Proceedings of the 2nd Conference on Generative Approaches to Language Acquisition North America, 180–187.
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