My father thinks I should stop smoking. * In this sentence, the verb think is a state verb. It is generally not used in the progressive (~ing) tense.

There are twenty-two students. We commonly used there is/are to express existence.

He is not really nice-looking, and yet he has enormous charm. Use a comma before any coordinating conjunction connecting two independent clauses.

Use a comma before and when adding three items or more.

Don't use THE when talking about things in general.

You don't need commas if "and" is used to indicate addition.

Everyone has seen that movie.

If we are late, they will be angry. * Being late is a real possibility, so you should use the first conditional.

IBGE, the Brazilian Institute of Geography and Statistics, is an important institution. Don't take for granted that your readers know things.

If I were a child, I would play outside. * Second conditional = If + past tense, subject + would/could/might. The second conditional is used for unreal cases.

My sister is being annoying today, but usually she is nice. (We use progressive tenses for actions that are temporary)

I have not eaten anything today.