expression: have you ever

Today ive learned a really useful sentence pattern which works in the same way as "have you ever" in English.
Its quite simple and can apparently be used like this:
Anh         (đã) từng   đến    Nha Trang    chưa?
Subject+ đã từng + Verb + (Object) +  chưa?
Do you guys know any other variations of this, like how would i for example say
"have you(group of people) already had lunch?"