Children often produce nonadult responses to sentences with the focus operator only, such as "Only the cat is holding a flag." For example, children often accept this sentence as a description of a situation in which a cat holds a flag and a duck holds both a flag and a balloon. One proposed analysis, by Paterson, Liversedge, Rowland & Filik…

In the 1980s, researchers in child language devised several new experimental techniques to assess children's emerging linguistic competence. Innovations in methodology were needed to bridge the apparent gap between the expectation of rapid language acquisition, based on linguistic theory, and the protracted acquisition that was being witnessed…