Syntax constrains the acquisition of verb meaning

Can infants use the syntactic context of an unknown word to infer that it is a verb, and thus refers to an action? Twenty-three-month-old French infants watching a moving object were taught novel verbs, within sentences that contained only function words (e.g. “il poune par là” / “it’s pooning there”). Infants then watched two instances of the object undergoing either the familiar or a novel action and were asked to point towards the screen matching the novel verb. Infants correctly pointed more often towards the familiar action. To check that they did not simply perseverate in pointing at the familiar scene, control infants were taught novel nouns on the same visual stimuli (e.g. “un poune est là”/ “a poon is here”). Contrary to verb-learning infants, noun-learning infants pointed more often to the novel action. These results confirm the hypothesis that function words, and more generally syntactic structure, support early lexical acquisition.