"Those boys are big."
Translation:Ti chlapci jsou velicí.
"Ti/tamti/tamhleti chlapci/kluci/hoši jsou velicí". 'Jsou' shouldn't stand at the beginning unless you want to ask a question.
What's the difference between velicí and velcí? It did accept velcí for me so is it always interchangeable? I think I've read it before but can't find it