Verified answer

Almorzar wouldn't make sense at all. I would use encontrar ("encuentran ustedes para almorzar"/ "encontrar a ustedes para almorzar"). But of course, that depends on what the other questions are, because encontrar could apply better to another question, seeing that the other verbs could also be used in this sentence.

I'm a native speaker, and I am perplexed. Almorzar make no sense. Eat lunch you to eat lunch? All the others except poder could make gramatical sense if that is what you wanted to say, but you would have to either conjugate it or add an a. For example, ?Encontrar a ustedes para almorzar? Find you to go to lunch? ?Recordar a ustedes para almorzar? Remmember you to go to lunch with? Return (like a package) you in order to go to lunch? ?Devolver a ustedes para almorzar? Poder would have to be conjugated, ¿Pueden ir ustedes a almorzar? What is the context? Perhaps I can help you if I know more.

¿Vuelven ustedes para almorzar? = Are you coming back for lunch?