Telling how much space left in linux

On windows, I can easily know how much space is left on disk with DIR. But on this linux, ls doesn't show it. How do I tell?

Oh Noes!  Don't make me learn something new!  OMG Why isn't linux just like Windows and DOS?  Learning the differences is unpossible!  If they would just create a search engine where I could type what I wanted and it would give answers! I'll call it "Google"  and I would just have to type "linux disk space" and the first result would give me my desired answer!!!!