She has a two-year-old daughter.

My niece is a one-year-old baby.

My one-year-old daughter just started walking.

I tried a thousand-year-old egg for the first time and it was surprisingly delicious.

I tried thousand-year-old eggs for the first time and they were delicious.

The park is filled with one-year-olds playing on the swings.

I just found out that I'm today years old.

I'm twenty years old.

I am twenty years old