Sentences can be classified according to their functions. There are four sentence functions in English: declarative, exclamatory, interrogative and imperative.
Declarative sentences state an idea. They end with a full stop.
- Susie smokes.
- The war is over.
- Three students failed to sit the examination.
- I am not ready yet.
Exclamatory sentences express strong emotions. They end with an exclamation mark. Examples are:
- What a lovely day it is!
- I can’t believe this!
- What a mess this room is!
- How beautiful it is!
Interrogative sentences ask a question. They end with a question mark.
- Is Susie drinking tea?
- What is Susie drinking?
- Who are you?
Imperative sentences give orders or directions. They end with a period or an exclamation mark.
- Wash your hands.
- Do your homework!
- Sit down and listen!
An imperative sentence usually has no expressed subject (though you is understood as its subject).