Clauses
A clause is a group of words that contains a subject and a verb. Understanding clauses is the foundation of understanding how sentences work in English.
What is a clause?
A clause is a group of words that contains both a subject (who or what the clause is about) and a finite verb (a verb that shows tense). This is what separates a clause from a phrase — phrases lack a subject-verb combination.
| Group of words | Subject? | Verb? | Is it a clause? |
|---|---|---|---|
| the tall teacher | ✗ | ✗ | No — it's a phrase |
| running quickly | ✗ | ✗ (no tense) | No — it's a phrase |
| she laughed | ✓ (she) | ✓ (laughed) | Yes |
| because it was raining | ✓ (it) | ✓ (was) | Yes |
The two main types of clause
Every clause is either independent (main) or dependent (subordinate).
| Type | Can stand alone? | Example |
|---|---|---|
| Independent (main) | Yes — forms a complete sentence | She smiled. |
| Dependent (subordinate) | No — needs a main clause | because she was happy |
She smiled [independent] because she was happy [dependent].
The book [phrase] that he recommended [dependent] was excellent [independent].
After the rain stopped [dependent], the children played outside [independent].
Types of dependent clause
- Adverbial clauses — act like adverbs, modifying the main verb: She left before he arrived.
- Relative clauses — describe a noun: The man who called is my uncle.
- Noun clauses — act as a subject or object: What she said surprised me.
Adverbial: He left early so that he could catch the train.
Relative: The café where we met has closed down.
Noun: I know that she is right.
Clauses and sentence types
| Sentence type | Clause structure | Example |
|---|---|---|
| Simple | 1 independent clause | She sings. |
| Compound | 2+ independent clauses | She sings, and he plays guitar. |
| Complex | 1 independent + 1+ dependent | She sings when she is happy. |
| Compound-complex | 2+ independent + 1+ dependent | She sings when she is happy, and he always listens. |
Clause ≠ sentence: A clause can be a sentence (if independent), but not every clause is a sentence. A dependent clause used alone is a sentence fragment.
Tip: To spot a clause, look for a subject + finite verb pair. If you find one, you have a clause. If the clause makes complete sense alone, it's independent. If it leaves you asking "so what?", it's dependent.