Simple, Compound and Complex Sentences: Rules, Examples and Worksheet
Learn the rules with pictures, then play the games.
A sentence can be simple, compound, complex or compound-complex, and the type depends on its clauses. An independent clause makes sense on its own, so this page draws it as an engine that can go by itself. A dependent clause has a subject and a verb but cannot stand alone, so it is a carriage that needs an engine. Coordinating conjunctions, the FANBOYS words, join two independent clauses. Subordinating conjunctions such as because, when and although start a dependent clause. Below you will find the four sentence types with examples, three tests you can run on any sentence, a Doubt Buster for the questions students ask most, ten practice questions with answers and a free PDF worksheet with an answer key. When you are ready, play the sentence games: eight levels of practice and a word garden where you build your own sentences.
Why a train?
An independent clause makes sense on its own, just as an engine can go on its own.
No independent clause, so this dependent clause cannot stand alone. On its own it is a fragment.
A dependent clause does not make sense alone, just as a carriage cannot go without an engine. Left alone, it is a fragment.
Join the dependent clause to an independent clause, and the train can go. Now it is a full sentence.
Two engines? Yes. Long, heavy trains often have two engines coupled together, and each engine could still run on its own. A compound sentence is the same: two independent clauses, each a full sentence on its own, joined by a conjunction such as and, but or so.
Simple, compound, complex and compound-complex sentences
A clause is a group of words with a subject (a noun or pronoun: who or what) and a verb (the doing or being word). How many clauses a sentence has, and what kind they are, decides its type.
- independent clause (engine)
- dependent clause (carriage)
- conjunction (hook)
Simple sentence 1 independent clause
One independent clause.
Compound sentence 2+ independent clauses + a conjunction
Two or more independent clauses joined by for, and, nor, but, or, yet, so (or a semicolon).
Complex sentence 1 independent + 1 dependent clause
One independent clause and at least one dependent clause.
Compound-complex sentence 2+ independent + 1 dependent clause
Two or more independent clauses and at least one dependent clause.
Three tests you can run on any sentence
Find the subject and the verb. Find each verb (doing word), then ask who or what does it. That noun or pronoun is the subject. Every subject and verb pair is one clause.
Stand Alone. Cover everything else. Can this clause be a sentence by itself? Yes means independent clause. No means dependent clause.
Count the clauses. Count the independent and dependent clauses, then read the type from the four boxes above.
Ready to try? Build trains of clauses in eight game levels and a word garden.
▶ Play the sentence gamesCoordinating and subordinating conjunctions
The joining word tells you the type. A coordinating conjunction (FANBOYS) joins two independent clauses and makes a compound sentence. A subordinating conjunction starts a dependent clause and makes a complex sentence.
FANBOYS: coordinating conjunctions
- for gives a reason
- and adds
- nor adds another no
- but shows a surprise
- or gives a choice
- yet shows a surprise
- so shows a result
Subordinating conjunctions and relative pronouns
- Dependent clause first? Put a comma before the independent clause: When the bell rang, we ran out.
- Independent clause first? Usually no comma: We ran out when the bell rang.
Doubt Buster: the questions students ask most
Tap a question to open it. The game links here whenever a doubt trips you up.
If a sentence has and in it, is it compound?
Not always. Ali and Sara played. is a simple sentence. And joins two names into one subject, so there is still only one clause. A sentence is compound only when and joins two full clauses, each with its own subject and verb: Ali played, and Sara read.
Is a long sentence always complex?
No. Complex means it has a dependent clause, not that it is long or hard. Early on a cold morning, the old farmer slowly walked to the barn with his two dogs. is long but simple: one subject, one verb. It rained, so we stayed in. is short but compound.
How do I find the subject and the verb?
Find the action first. That is the verb, together with any helper words such as is, was, have or will. Then ask who or what did it. That is the subject. A noun after a small word like in, on, of or with is never the subject: in The children in the back row cheered, the subject is the children, not the row.
What is a sentence fragment?
A piece of a sentence written as if it were whole. It may have no subject (Running down the hill.), no verb (The man with the blue umbrella.), or it may be a dependent clause left on its own (Because I was hungry.). Fix it by adding the missing part or by joining it to an independent clause.
Which words start a dependent clause?
The most common subordinating conjunctions are because, although, though, even though, when, while, whenever, if, unless, until, before, after, since, as, so that, where, and the relative words who, whom, whose, which and that. If a clause starts with one of these, it usually cannot stand alone.
What are the FANBOYS?
The seven coordinating conjunctions: for, and, nor, but, or, yet, so. They are the only words that can join two independent clauses after a comma. And adds, but and yet show a surprise, or gives a choice, so shows a result, for gives a reason, nor adds another negative.
When does a complex sentence need a comma?
When the dependent clause comes first: Because it was raining, we stayed inside. When the independent clause comes first, you usually do not need one: We stayed inside because it was raining.
What is a comma splice?
Two independent clauses joined by a comma alone, such as The phone rang, nobody answered. A comma cannot hold two independent clauses together. Fix it with a FANBOYS word (The phone rang, but nobody answered.), a semicolon, or a full stop.
Are however and then joining words like but?
No. However, therefore, then and also are not FANBOYS, so a comma alone cannot join two clauses with them. Write It was late; however, we kept going. or use two sentences. A sentence joined by a semicolon still counts as compound, because both halves are independent clauses.
Does a who or which clause make a sentence complex?
Yes. In My aunt, who is a doctor, works at night. the part who is a doctor has its own subject and verb but cannot stand alone. It is a dependent clause, so the sentence is complex, even though the clause sits in the middle.
Who lives next door? is a question. So is who lives next door a dependent clause or not?
It depends on the job it does. With a capital letter and a question mark, Who lives next door? is a full question, so it is a simple sentence. Inside a longer sentence, as in The man who lives next door has a dog., the same words only tell us which man. There they are a dependent clause.
Can a sentence start with because?
Yes, as long as an independent clause follows. Because I was hungry, I ate an apple. is a correct complex sentence. Because I was hungry. on its own is a fragment.
Is so always a FANBOYS word?
Only when it means as a result: It was cold, so I wore a coat. So that means in order that, and it starts a dependent clause: I wore a coat so that I would stay warm. That second sentence is complex.
What is a compound-complex sentence?
A sentence with at least two independent clauses and at least one dependent clause. When the wind dropped, the kite fell, and my brother caught it. has two independent clauses (the kite fell, my brother caught it) and one dependent clause (when the wind dropped).
Simple, compound and complex sentences: practice questions with answers
Ten questions to try on paper or out loud. Answer first, then open the answer to check.
1. What type of sentence is this? The children laughed and clapped.
Show the answer
Answer: Simple. One subject (the children) with two verbs. There is only one clause.
2. What type of sentence is this? The children laughed, and the teacher smiled.
Show the answer
Answer: Compound. Two independent clauses joined by the coordinating conjunction and.
3. What type of sentence is this? The children laughed when the clown fell over.
Show the answer
Answer: Complex. One independent clause (the children laughed) and one dependent clause (when the clown fell over).
4. What type of sentence is this? When the clown fell over, the children laughed, but the baby cried.
Show the answer
Answer: Compound-complex. Two independent clauses joined by but, plus the dependent clause when the clown fell over.
5. Is this a full sentence or a fragment? After the match ended.
Show the answer
Answer: Fragment. After makes this a dependent clause. It needs an independent clause, for example: After the match ended, we went home.
6. Join these with a FANBOYS word: I was late. I missed the bus.
Show the answer
Answer: I was late, so I missed the bus.. Missing the bus is a result, so the coordinating conjunction so fits. The result is a compound sentence.
7. Join these to make a complex sentence: I missed the bus. I was late.
Show the answer
Answer: I missed the bus because I was late.. Because turns I was late into a dependent clause that gives the reason.
8. Find the dependent clause: The book that you lent me is very good.
Show the answer
Answer: that you lent me. It has a subject (you) and a verb (lent) but cannot stand alone. It tells us which book.
9. Correct the comma splice: It was cold, we wore our coats.
Show the answer
Answer: It was cold, so we wore our coats.. A comma cannot join two independent clauses alone. Adding so makes a correct compound sentence. A full stop or a semicolon also works.
10. What type of sentence is this? Close the door.
Show the answer
Answer: Simple. An order with the hidden subject you: (You) close the door. One clause, so it is simple.
Free PDF: simple, compound and complex sentences worksheet with answers
Five pages: a one page rules chart, 64 questions in eight sections that follow the game, and a full answer key. Print it for class, homework or revision.
Download the PDF worksheetQuestions parents and teachers ask
Is this free?
Yes. The lesson, the games, the hints and the printable PDF worksheet are all free, with no sign up. Game progress is kept on your own device only.
Which classes is this for?
Levels 1 to 4 suit children from about age 8, Class 3 or Grade 3 upwards. Levels 5 to 8 cover compound, complex and compound-complex sentences, which are taught from about age 10 up to secondary school, Class 9 and 10.
Is there a printable worksheet with answers?
Yes. The PDF worksheet has a one page rules chart, eight sections of questions that follow the game levels, and a full answer key at the end. It is free to print for class or home.