Without the appropriate Chinese definition of "lost" in the word, you are guessing what word means lost without context clues
How about ,, get lost,,
lost could also mean losing a competition
In English that would be "I think we have lost" rather than "are lost"
"we are lost" almost exclusively means "we can't find our way" , at least in American English (the other alternative being a rather poetic "our lives are forfeit") while losing a competition is expressed as "we have lost" or "we are losing"
In that case, you would say "I think we lost" not "I think we are lost".
Yes, but you would say "have lost" if you're using that meaning of the word lost. If you "are lost", then you don't know the way or you don't know what to do.
The translation in that case would be; I think we have lost.