There are four kinds of sentences:
1. Assertive or declarative sentence (a statement)
2. Imperative sentence (a command)
3. Interrogative sentence (a question)
4. Exclamatory sentence (an exclamation)

1. An assertive sentence is a sentence that states a fact. Such sentences are simple statements. They state, assert, or declare something.
Examples:
Jan is a student. She lives in a big city.

2. Imperative sentence is a sentence which gives a command, makes a request, or express a wish.
Examples:
Go to your room. (an order)
Please lend me your book. (a request)
Have a good time at the picnic. (a wish)

3. Exclamatory sentence is a sentence that expresses sudden and strong feelings, such as surprise, wonder, pity, sympathy, happiness, or gratitude.
Example:
What a shame!
Boy, am I tired!

4. Interrogative sentence: A sentence that asks a question is called an interrogative sentence.
Examples:
What is your name?
Where do you live?