This special issue commentary draws seven lessons from the four papers on input and bilingual development: (1) the environments in which children become bilingual vary widely, (2) capturing the relevant features of those environments is difficult, (3) input is shaped by the larger social context, (4) language skill is multifaceted, (5) the relation of input to language skill may be different for different facets of language, (6) not just input, but also language use affect language development, (7) studies of the relation of input to bilingual development provide a unique window onto basic processes of language development.