Present Simple, Present Continuous and Present Perfect. Revision on why we use them
Present Simple is used to express facts in the present, Present Continuous is used to express processes in the present and Present Perfect is used to express actions that have already happened and have a connection with the present moment or results.
I like to read books. (Fact in the present.)
He plays tennis every week. (Fact in the present.)
He is reading a book right now. (Process in the present.)
We are playing football now. (Process in the present.)
Mother has cooked a dinner. It is on the table. (Finished fact, which has a connection with the present.)
I have already done my homework. (The action has already happened.)