Birth: Early crying, babies’ attempt to communicate

5 months: Cooing, making sounds like ga-ga, gu-gu

1^st birthday: a few words like doggie, milk, dada

18 months~24 months: 2-word phrases such as eat now or baby cry

2 years~: Acquisition of  about 200 new words a month

2.5 years: 3-word sentences such as no want carrots

5 years: Understanding and correct production of grammar