Identify a Compound Sentence

Twins

Jake and Matt are identical twins. They are the same age and the same height. They both have brown hair and brown eyes. Their physical make-up is very similar. But in some ways, they are different. Jake likes running, while Matt prefers swimming. Matt likes reading mysteries, and Jake prefers comic books.

In English grammar, a compound sentence is a bit like twins. There are two parts. Each part is equal in structure, but different in the details. In this lesson, we will explore compound sentences. Before we do, let's review some facts about sentences.

Facts About Sentences

• A sentence begins with a capital letter.
  Matt read a book about detectives.
• A sentence ends with a punctuation mark: a period ( . ), question mark (?), or exclamation point (!).
  Did Jake read the same book?
• A sentence expresses a complete thought.
  Sentence: Jake won a race.
  Not a sentence: won a race
• A sentence must have a subject. The subject tells who or what the sentence is about.
  Matt swims every day. The subject is Matt.
• A sentence must have a verb. The verb can be an action verb, telling what the subject does. It can also be a linking verb, telling what the subject is by connecting the subject to a subject complement - a word that renames or describes the subject.
  The pool is cold. (linking verb)
  Matt shivers. (action verb)

Building a Compound Sentence

Now that we have reviewed sentences, it's time to learn about compound sentences. A compound sentence consists of two or more independent clauses joined by a comma and a coordinating conjunction. Let's examine the parts of this definition.

Independent Clause

An independent clause is a group of words with a subject and verb that expresses a complete thought.

Independent clause: Jake ran two miles (subject: Jake; verb: ran; expresses a complete thought)

Not an independent clause: when he got home (subject: he; verb: got; does not express a complete thought)

We should note that an independent clause only contains one subject/verb pairing, but it can contain a compound subject or verb. Look at these independent clauses.

Compound subject: Jake and Matt live in Texas. (subjects: Jake, Matt; verb: live) Compound verb: Their grandma lives and works in Montana. (subject: grandma; verbs: lives works)

Coordinating Conjunction

Our definition of a compound sentence said that two or more independent clauses are joined by a comma and a coordinating conjunction. We may know that a comma ( , ) is a punctuation mark that shows a pause. A coordinating conjunction is a word that connects words, phrases, or clauses that are parallel in structure. There are seven coordinating conjunctions: for, and, nor, but, or, yet, so. The acronym FANBOYS can help you remember these conjunctions.

Putting the Sentence Together

Jake got new running shoes, but Matt got new swimming goggles.

This is a compound sentence. Look:

• Independent clause #1: Jake got new running shoes
• Independent clause #2: Matt got new swimming goggles
• Joined by a comma and coordinating conjunction: , but

Jake won a race, so Matt was jealous.

This is also a compound sentence.

• Independent clause #1: Jake won a race
• Independent clause #2: Matt was jealous
• Joined by a comma and coordinating conjunction: , so

Finding Compound Sentences

How well do you understand compound sentences? Look at the following sentences and decide whether or not they are compound sentences.

• Matt likes broccoli, but Jake hates it.
  Independent clauses: Matt likes broccoli. Jake hates it.
  Joined by a comma and coordinating conjunction: , but
  Yes, this is a compound sentence.
• Matt likes broccoli but not spinach.
  Independent clause: Matt likes broccoli but not spinach.
  There is only one independent clause. The coordinating conjunction 'but' is joining the two direct objects - the two words that tell what Matt likes.
  This is not a compound sentence.
• Jake hates broccoli, yet he continues to eat it.
  Independent clauses: Jake hates broccoli. He continues to eat it.
  Joined by a comma and coordinating conjunction: , yet
  Yes, this is a compound sentence.
• Since Matt likes broccoli, he asks for more.
  Independent clause: he asks for more.
  'Since Matt likes broccoli' is a dependent clause - it does not express a complete thought.
  This is not a compound sentence.