[English study] 13 years old vs 13 year old

We already studied the expression about notation.  I left an example with hundred and hundreds expression in the previous posting.

In this case, I am going to handle another expression of notation for age.

There are some examples for this.

(1) I am 13 years old. (O)
(2) I am 13 year old. (X)

When you say your age to somebody, and you use this expression as complement, you should add 's' after the expression of YEAR.

(3) There is a 13 years old boy. (X)
(4) There is a 13 year old boy. (O)

When you indicate someone's age, and the expression is used as adjective in the sentence, you don't have to add 's' after the expression of YEAR.

You know always there are lots of exceptions in English, but what matter are they? That's why we are studying. Language is changing now.

See you next time.