How to distinguish declarative sentences, rhetorical questions, interrogative sentences and imperative sentences

A declarative sentence tells a story in a plain tone and usually ends with a period.

The tone of the rhetorical question, you know the answer from the sentence that has not been answered. Usually ends with a question mark.

Interrogative questions have doubts about this matter. If you don't understand, just wait for someone else to answer. It ends with a question mark.

Imperative sentences tell you how to deal with commands and warnings. Generally, the subject you is omitted, so there is no room for refutation. It ends with an exclamation point.

The above is my personal opinion, I hope it will help you.