Today, I’d like to introduce the Kanji, ‘歳（さい） and ‘才（さい）.’
Both of them are often used in the sense of age, for example, “20歳（20才）” means “twenty years old.”
However, only ‘歳’ is the precise kanji as the meaning of ‘age.’
In fact, ‘才’ means talent of ‘ability.’
A common point of these kanji was how to read it.
Since ‘才’ is more easy to write, we got to use it as a abbreviation of ‘歳’.
However, ‘才’ is just an abbreviation, so we should use ‘歳’ in the formal situation.
