How do you say understand much French in french?

The most natural way to say "understand much French" in French is:

"Je comprends beaucoup de français."

Here's a breakdown:

* Je: I

* comprends: understand (present tense of "comprendre")

* beaucoup: much, a lot

* de: of

* français: French

You could also say:

* "Je comprends bien le français." (I understand French well)

* "Je parle un peu français." (I speak a little French)

The best choice will depend on the context and your level of French understanding.