In English grammar, sentences are categorized based on their purpose or function. There are four main types of sentences: Assertive, Interrogative, Imperative, and Exclamatory. Understanding these helps us express ourselves more clearly and correctly.

Types of Sentences by Function (Purpose) :

1.  Assertive Sentences (Also called Declarative Sentences)

These are simple statements that give information or express an idea, opinion, or fact.
They can be positive (affirmative) or negative.

• Example (Positive): She is a good teacher.

• Example (Negative): He does not like coffee.

2.  Interrogative Sentences

These are questions. They are used to ask for information and always end with a question mark (?).
They usually start with helping verbs (Do/Does/Is/Are) or question words (What, Why, Where, When, How).

• Example: What are you doing?

• Example: Is he coming today?

3.  Imperative Sentences

These sentences give commands, advice, instructions, or requests. The subject is usually understood to be “you.”

• Example (Command): Close the door.

• Example (Request): Please help me with this.

4.  Exclamatory Sentences

These show strong emotions like surprise, happiness, anger, or excitement, and end with an exclamation mark (!).

• Example: What a beautiful place!

• Example: I can’t believe this!

Understanding these sentence types helps learners form correct and meaningful expressions in both spoken and written English.

Types of Sentences by Structure : 

a) Simple Sentence :

A sentence with one independent clause.

Examples:

• He plays football.

• I love ice cream.

• The birds are flying.

 b) Compound Sentence :

A sentence with two independent clauses joined by coordinating conjunctions like and, but, or, so, yet, for, nor.

Examples:

• I was tired, but I finished my work.

• She loves to read, and he enjoys music.

 c) Complex Sentence :

A sentence with one independent clause and one or more dependent clauses.

Examples:

• When I was a child, I loved cartoons.

• She didn’t come because she was ill.

 d) Compound-Complex Sentence : 

A sentence that contains at least two independent clauses and at least one dependent clause.

Examples:

• I was late because I missed the bus, but my teacher understood.

• Although it was raining, we went for a walk, and we enjoyed it.