In many so-called canonical null subject languages, null and overt subject pronouns have contrasting referential preferences: null subjects tend to maintain reference to the preceding subject while overt pronominal subjects do not. We propose that children acquire this contrast by initially restricting their attention to 1st and 2nd person…

Non-tone language infants' native language recognition is based first on supra-segmental then segmental cues, but this trajectory is unknown for tone-language infants. This study investigated non-tone (English) and tone (Thai) language 6- to 10-month-old infants' preference for English vs. Thai one-syllable words (containing segmental and tone…

Visually situated spoken words activate phonological, visual, and semantic representations guiding overt attention during visual exploration. We compared the activation of these representations in children with and without developmental language disorder (DLD) across four eye-tracking experiments, with a particular focus on visual (shape)…

Does language development drive language change? A common account of language change attributes the regularity of certain patterns to children's learning biases. The present study examines these predictions for change-in-progress in the use of "must" in Toronto English. Historically, modal verbs like "must" start with root…

Beginning with the classic work of Shepard, Hovland, & Jenkins (1961), Type II visual patterns (e.g., exemplars are large white squares OR small black triangles) have held a special place in investigations of human learning. Recent research on Type II "linguistic" patterns has shown that they are relatively frequent across languages…

From an early age, children apply the mutual exclusivity (ME) assumption, demonstrating preference for one-to-one mappings between words and their referents. However, for the acquisition of referentially overlapping terms, ME use must be suspended. We test whether contextual cues to intended meaning, in the form of presence of a speaker, may be…

We report on two experiments that investigated the acquisition of the Tagalog symmetrical voice system, a typologically rare feature of Western Austronesian languages in which there are more than one basic transitive construction and no preference for agents to be syntactic subjects. In the experiments, 3-, 5-, and 7-year-old Tagalog-speaking…

Onomatopoeia are disproportionately high in number in infants' early words compared to adult language. Studies of infant language perception have proposed an iconic advantage for onomatopoeia, which may make them easier for infants to learn. This study analyses infants' early word production to show a phonological motivation for onomatopoeia in…

Languages differ in how they encode causal events, placing greater or lesser emphasis on the agent or patient of the action. Little is known about how these preferences emerge and the relative influence of cognitive biases and language-specific input at different stages in development. In these studies, we investigated the emergence of sentence…

Infants are thought to be sensitive to frequency in the input as a cue for phonological development. However, linguistic biases such as phonological markedness have been argued to play a role too. Since frequency and markedness are correlated, the two assertions could be different interpretations of data that confound frequency and markedness. In…

We tested 12- and 18-month-old English-learning infants on a preferential-looking task which contrasted grammatically correct sentences using the determiner "the" vs. three ungrammatical conditions in which "the" was substituted by another English function word, a nonsense word, or omitted. Our design involved strict controls…

The infant brain may be predisposed to identify perceptually salient cues that are common to both signed and spoken languages. Recent theory based on spoken languages has advanced sonority as one of these potential language acquisition cues. Using a preferential looking paradigm with an infrared eye tracker, we explored visual attention of hearing…

Syntactic bootstrapping facilitates children's initial learning of verb meanings based on syntactic information. A challenging case is the argument-drop languages, where the number of argument NPs is not a reliable cue for distinguishing between transitive and intransitive verbs. Despite this fact, the availability of syntactic bootstrapping in…

Infants' disposition to learn repetitions in the input structure has been demonstrated in pattern generalization (e.g., learning the pattern ABB from the token "ledidi"). This study tested whether a repetition advantage can also be found in lexical learning (i.e., learning the word "lele" vs. "ledi"). Twenty-four…

When learning verb meanings, learners capitalize on universal linguistic correspondences between syntactic and semantic structure. For instance, upon hearing the transitive sentence "the boy is glorping the girl," 2-year-olds prefer a two-participant event (e.g., a boy making a girl spin) over two simultaneous one-participant events (a…