1. present simple / present continuous
present simple :
I eat loads of chocolate during the weekend.
Present continuous: The girl is chewing her food very obviously. I can't stand that. The NOISE!
difference of form: eat/ eats vs am/is/are + ww+ ing ( am eating)
difference of usage: habits and facts (that pizza looks delicious)
something that is happening over a period of time ( He is saving all his money for his driving lessons )