The inquiry of bilingual development has been, and must be, an interdisciplinary aspiration; Carroll presents us with a viewpoint from within one specific discipline, that of generative linguistics. From this vantage point, she supplies us perhaps most importantly with the keepsake that language is not a unitary construct, and cautions against extrapolating from findings on the learning of one specific aspect of language, like vocabulary, to language acquisition more broadly. This paper concurs (for a similar point, see Paradis & Grüter, 2014). It does not concur, however, with Carroll's implication that such unjustified extrapolation is characteristic of current inquiry on input and bilingual development. A number of recent studies have looked specifically at the differential relation between input (in a broad 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.