How do you say I speak English only in french?

There are a few ways to say "I speak English only" in French, depending on the level of formality and the nuance you want to convey:

Formal:

* Je ne parle que l'anglais. (This is the most direct and literal translation.)

* Je parle uniquement l'anglais. (This emphasizes the exclusivity of English.)

Informal:

* Je parle seulement anglais. (This is a more casual way to say it.)

* Je suis anglophone. (This means "I am an English speaker.")

You can also add a phrase like "Je suis désolé, mais..." (I'm sorry, but...) or "Je comprends un peu de français, mais..." (I understand a little French, but...) to be more polite if you are in a situation where you need to explain that you don't speak French.