Ineed 5 affirmative and 5 negative in the tu form to have somebody successful in school. ( in commands) like: study all homework, etc.

Tu no hablas (you're not speaking) = "No hables" (don't speak)
Tu no comes (you're not eating) = "No comas" (don't eat)
Vosotros no hablais (you're [all] not speaking) = "No hableis" (don't speak)
Vosotros no comeis (you're [all] not eating) = "No comais" (don't eat) 
no habla (you're [formal] not speaking) = "No hable" (don't speak) 
no come (you're [formal] not eating) = "No coma" (don't eat)
so like this

An answer would be alphabti

Cusco is the oldest city