There are four basic types of sentences: declarative, imperative, interrogative, and exclamatory.
Declarative – You are invited to join us for lunch.
Imperative – Please join us for lunch.
Interrogative – Would you like to join us for lunch?
Exclamatory – I’m so glad you can join us!
Declarative sentences make a statement, whereas interrogative sentences ask a question. Imperative sentences convey a command, and exclamatory sentences express a strong emotion.