Formal:
* คุณพูดภาษาอังกฤษได้ไหมคะ/ครับ? (khun poot basa angkrit dai mai ka/krap?)
* This is the most polite and formal way to ask.
* "ka" is used for females, "krap" for males.
Informal:
* พูดภาษาอังกฤษได้ไหม? (poot basa angkrit dai mai?)
* This is a more casual way to ask.
* You can use "ka" or "krap" at the end, but it's not necessary.
Even more informal:
* พูดอังกฤษได้ป่ะ? (poot angkrit dai pa?)
* This is very informal and should only be used with close friends.
* "pa" is short for "pai" which means "or not?".
It's important to choose the appropriate level of formality depending on who you are speaking to. If you're unsure, it's always better to be more formal.