"Do you speak English?"

"Do you speak English?"

¡Hola!
(Este) Es mi primer o mensaje en español.
Mi pregunta es:
¿"Uso/tengo que usar" '¿Tú hablas inglés?' o '¿Usted habla inglés?'
con los desconocidos?(I'd say: ¿Qué es mejor utilizar con personas desconcidas "¿Tú..." o "¿Usted..." ?)


I think what you mean for "strangers" is people that you meet for the first time, the polite course to take in this situation is to use formal speaking. Therefore, you should use "usted" or "ustedes", avoid using "tú" if you're speaking with elders, once the person tells you it's ok to use "tú" with them, or you ask for permission to do it, then it would be correct.

You can use "tú" with people around your age or younger. But older people and formal situations(business meetings, job interviews etc, also adressing someone somehow prestigious like priests ,presidents, etc) require the use of "usted".