Formal:
* Je parle français. (This is the most common and literal translation.)
* Je suis capable de parler français. (This means "I am capable of speaking French.")
Informal:
* Je sais parler français. (This means "I know how to speak French.")
* Je parle un peu français. (This means "I speak a little French.")
If you want to emphasize your fluency, you can use:
* Je parle couramment français. (This means "I speak French fluently.")
You could also use:
* Je suis francophone. (This means "I am a French speaker.")
Choose the phrase that best suits the situation and your level of French.