At three months, a child:
Makes cooing and gurgling sounds
At six months, a child:
Babbles and makes sing-song sounds
At twelve months, a child:
Babbles, but with inflection, which sounds like talking
Says first word
At eighteen months, a child:
Says 8–10 words others can understand
Has vocabulary of about 5 to 40 words, mostly nouns
Repeats words heard in conversation
Uses “hi,” “bye,” and “please” when reminded
At two years, a child:
Has a vocabulary of 150 to 300 words
Uses 2–3 word sentences, usually in noun-verb combinations, such as “Dog bark,” but also using inflection with combinations like “More cookie?”
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