What are some english exercises I can use in classroom to teach English grammar?

Communicative exercises are the best.

Let's say you are doing a PPP (present, practice, produce). 

In the first P, you present grammar using context then you clarify.

In the second P, you give your student the chance to practice the peace of grammar that you are focusing on through a focus on form exercises. 

In the third P, you allow your student to produce the peace of grammar through communicative exercises or freer exercises.

Should be watch English General knowledge documentary films and prepare books of famous English liters