Je suis vs. J'ai

Question

Hi, I'm a beginner in French and I always get confused in using Je suis and J'ai. In my head (which thinks in English), sentences like 'I am 20 years old' is not 'Je suis vingt ans' but 'J'ai vingt ans' which literally means 'I have 20 years old'. Is there are hard rule when to use Je suis or J'ai in a sentence?

Accepted Answer

J'ai = I have.Je suis = I am.
That said, not always when you would say "I am" in English, is the French translation Je suis. The French say, e.g., I have 20 years (j'ai 20 ans). There are other examples, but they are, all in all, exceptions. Mostly, être and avoir are used as they are in English.
Don't get hung up on this, just continue studying. It will all fall in place eventually.

Answer

Bonjour Di,
To supplement Chris's answer, here are two links on idiomatic expressions with être vs avoir:
- Idiomatismes avec avoir
- Idiomatismes avec être
I hope this is helpful.
Bonne journée!