你在看电影吗？用英语怎么讲

必须用不定冠词a,因为正确的英语中,可数名词,从来都是和a,the或可数名词复数在一起的.

所以:
Are you watching a movie /film?

Are you watching movie?
Are you seeing a movie?

肯定对

Are you watching a movie?
或Are you watching movies~?

are you watching movie?
我想不用a了吧?

Are you watching movie?

Are you watching a film?