Birth: Early crying, babies’ attempt to communicate
5 months: Cooing, making sounds like ga-ga, gu-gu
1st 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