Writing Complete Sentences

You already know that a complete sentence has a subject and a predicate. Now you will learn to check your own sentences carefully. You will find sentence fragments, which are word groups missing a part, and run-on sentences, which are two sentences squished into one. Then you will fix both problems so every sentence you write tells one clear, whole thought.

Every complete sentence has two parts working together. The subject tells who or what the sentence is about. The predicate tells what the subject does or what happens to it.

Look at this sentence: "The puppy barks." The subject is "the puppy." The predicate is "barks." Together they tell a whole thought. You can picture exactly what is happening.

When you write your own sentences, ask yourself two questions. Who or what is this about? What does that subject do? If you can answer both, you have a complete sentence.

A sentence fragment is a group of words that looks like a sentence but is missing a part. It does not tell a whole thought, so it leaves you confused.

Look at "Runs across the yard." This is a fragment. It has a predicate, "runs across the yard," but it has no subject. Who runs? You do not know. You can fix it by adding a subject: "The dog runs across the yard."

Now look at "The little red truck." This is also a fragment. It has a subject, "the little red truck," but no predicate. What does the truck do? You can fix it by adding an action: "The little red truck stops."

When you check your writing, read each sentence and ask if it is missing a subject or a predicate. If it is missing one, add the missing part to make it complete.

A run-on sentence happens when you push two complete sentences together without a stop between them. It can be hard for a reader to tell where one idea ends and the next one begins.

Look at this run-on: "The cat jumped on the bed it fell asleep." This is really two complete thoughts stuck together. You can fix it by splitting it into two sentences: "The cat jumped on the bed. It fell asleep."

When you read your own writing out loud, listen for a place where you take a breath in the middle of a long sentence. That spot is often where you need to stop and start a new sentence.

Complete Sentence: A group of words with a subject and a predicate that tells one whole thought.

Subject: The word or words that tell who or what the sentence is about.

Predicate: The word or words that tell what the subject does.

Sentence Fragment: A group of words that is missing a subject or a predicate.

Run-On Sentence: Two complete sentences joined together without a stop between them.

Read short word groups and decide if each one is a complete sentence, a fragment, or a run-on. For a fragment, add the missing subject or predicate. For a run-on, find the spot to split it into two sentences.

Try writing three complete sentences about your day. Check each one for a subject and a predicate. Then try reading them out loud to listen for any place that sounds like two ideas squeezed together.

Related lessons

• Complete Sentences