The study of bilingual development has been, and must be, an interdisciplinary endeavor; Carroll (Carroll) presents us with a perspective from within one particular discipline, that of generative linguistics. From this vantage point, she provides us perhaps most importantly with the reminder that language is not a unitary construct, and cautions against extrapolating from findings on the learning of one particular aspect of language, such as vocabulary, to language acquisition more broadly. I wholeheartedly agree (for a similar point, see Paradis & Grüter, 2014). I do not agree, however, with Carroll's implication that such unwarranted extrapolation is characteristic of current research on input and bilingual development. A number of recent studies have looked specifically at the differential relation between input (in a wide sense) and bilingual children's acquisition of different linguistic phenomena. Unsworth (2014), for example, reported different effects of input variation on Dutch–English bilingual children's acquisition of grammatical gender versus indefinite object scrambling.