J'ai deux ans.
This translates directly to "I have two years."
Here's a breakdown:
* J' is the contraction of "je" (I) and "ai" (have)
* deux means "two"
* ans means "years"
You can also say:
* Je suis âgé(e) de deux ans. This translates to "I am aged of two years."
* J'ai 2 ans. This is a shorter and more informal version.
The choice of which phrase to use depends on the context and your desired level of formality.