This cheat sheet explains how simple, compound, and complex sentences are built from clauses. Students need these patterns to write clearer, more varied sentences and to avoid fragments and run-ons. It is especially useful for grammar review, sentence combining, editing, and improving paragraph flow.
The main idea is that every complete sentence needs at least one independent clause. A simple sentence has one independent clause, a compound sentence joins two independent clauses, and a complex sentence combines an independent clause with a dependent clause. Coordinating conjunctions, subordinating conjunctions, and correct punctuation help show how ideas are connected.
Key Facts
- An independent clause has a subject and a predicate and can stand alone as a complete sentence.
- A dependent clause has a subject and a predicate but cannot stand alone as a complete sentence.
- A simple sentence follows this pattern: independent clause.
- A compound sentence follows this pattern: independent clause + comma + coordinating conjunction + independent clause.
- The coordinating conjunctions are for, and, nor, but, or, yet, and so, often remembered as FANBOYS.
- A complex sentence follows this pattern: independent clause + dependent clause, or dependent clause + comma + independent clause.
- Use a comma after a dependent clause when it comes before the independent clause, as in Because it rained, we stayed inside.
- Do not use a comma before a dependent clause that comes after the independent clause unless the sentence needs a pause for clarity.
Vocabulary
- Clause
- A clause is a group of words that has a subject and a predicate.
- Independent Clause
- An independent clause is a complete thought that can stand alone as a sentence.
- Dependent Clause
- A dependent clause has a subject and predicate but does not express a complete thought by itself.
- Simple Sentence
- A simple sentence contains one independent clause and no dependent clauses.
- Compound Sentence
- A compound sentence joins two or more independent clauses.
- Complex Sentence
- A complex sentence contains one independent clause and at least one dependent clause.
Common Mistakes to Avoid
- Calling a long sentence a compound sentence is wrong because sentence type depends on clauses, not length.
- Writing a dependent clause as a sentence creates a fragment because the thought is incomplete, as in Although I was tired.
- Joining two independent clauses with only a comma creates a comma splice because a comma alone cannot connect complete sentences.
- Forgetting the comma in a compound sentence can make the relationship between two independent clauses unclear.
- Putting a comma before every because clause is wrong because a dependent clause at the end usually does not need a comma.
Practice Questions
- 1 Identify the sentence type: The dog barked loudly at the mail carrier.
- 2 Identify the sentence type: I wanted to play outside, but the rain kept falling.
- 3 Add correct punctuation: Because the test was difficult many students studied after school.
- 4 Explain why this is not a complete sentence: When the bell rang.