... Children begin learning morphological rules such as plurals, as demonstrated by the `wug' test (one wug, two wugs). One-year-olds often substitute stops for fricatives (e.g. [top] `soap') ... vocabularies.112B. The sounds of child language acquisitionAccording to Fry (2007), it is difficult to test newborns, but we can measure their interest in speech sounds by measuring their sucking rate. ... the age of 4 or 5, children have mastered all but the trickiest sounds of their language (e.g. English [T]). At age 7 we see sophisticated sentence connectives like though and anyway. Passive...