Sentence structure describes how words, phrases, and clauses fit together. To identify the four common sentence structures, count the independent and dependent clauses.
The four sentence structures
An independent clause can stand alone as a sentence. A dependent clause is part of a larger clause or sentence. The examples below use the same event so you can see what each new clause adds.
| Structure | Independent clauses | Dependent clauses | Example |
|---|---|---|---|
| Simple | 1 | 0 | The bell rang. |
| Compound | 2 or more | 0 | The bell rang, and the students packed up. |
| Complex | 1 | 1 or more | When the bell rang, the students packed up. |
| Compound-complex | 2 or more | 1 or more | When the bell rang, the students packed up, and the teacher erased the board. |
How to count clauses
Find the verbs and see which subject goes with each. In The students packed up and left, the students is the subject of both verbs. The sentence has one independent clause. In The students packed up, and the teacher erased the board, each verb has its own subject, and each clause can stand alone. Helping verbs belong to the same verb group as the main verb, as in has been ringing.
Two punctuation checks
- Attach a dependent clause. When the bell rang. is a fragment in formal writing. When the bell rang, the students packed up. gives it a main clause.
- Join independent clauses with the right punctuation. The bell rang, the students packed up. is a comma splice. Add a coordinating conjunction after the comma, use a semicolon, or split the clauses into separate sentences.
