Learn Croatian: Idemo u kino? Može! - Shall we go to the cinema? Sure!

In Croatian, saying može is the most common casual way to agree to a proposal. It literally means "it can" (as in "it can be done"), but it is used exactly like "Sure!", "Okay!", or "Sounds good!" in English.

Is idemo specifically the word for "shall we go"?

No, idemo simply means "we go" or "we are going." In Croatian, you don't need a special word like "shall" to make a suggestion. You just use the regular present tense with a questioning tone of voice to say "Shall we go?" or "Let's go."

Why doesn't the word kino change its ending after the preposition u?

The preposition u (into/to) takes the accusative case here because it shows motion toward a destination. The word kino is a neuter noun. In Croatian, neuter nouns look exactly the same in the accusative case as they do in the nominative (dictionary) form, so the ending stays the same.