YOU SAID:

If I were one year older I would be twenty one.

INTO JAPANESE

もし私が1歳だったら、私は21歳になります。

BACK INTO ENGLISH

If I were 1 year old, I would be 21 years old.

INTO JAPANESE

私が1歳だったら、21歳になります。

BACK INTO ENGLISH

If I were 1 year old, I would be 21 years old.