who are more educated have larger vocabularies (Hoff, 2003).

In child-directed speech, utterances have several additional features. For example, the phonology in child-directed speech is different: Utterances are spoken more slowly, with longer pauses in between utterances, higher pitches, etc. The lexis and semantics differ, and a speaker uses words suited for children, "doggie" instead of "dog", for example. The grammar is simpler, repetitive, with less use of verbs and adjectives. There is a greater