我能讲日语吗用英语

Yes, you can say "I can speak Japanese" in English. Here are a few examples:

1. "Can you speak Japanese？"

2. "I can speak Japanese."

3. "Do you speak Japanese？"

If you need to express that you are capable of speaking Japanese, you can say "I can speak Japanese." This phrase is clear and polite, and it should be understood by most people who speak English.