Let’s talk about why a sentence gets labeled a fragment.
A fragment is a piece of something, so a sentence fragment is a piece of a sentence. A true sentence is a complete thought. With a sentence fragment, the thought is not complete.
Here are three common mistakes that cause a sentence fragment:
1. The writer forgot to put in a subject. We don’t know who is doing the action.
Fragment: Opened the door slowly
Sentence: Bob opened the door slowly.
2. The writer forgot to put in a verb. We don’t know what is happening in the sentence.
Fragment: The fourth grade teacher and his students
Sentence: The fourth grade teacher and his students watched a movie.
3. The writer used a subordinate clause but forgot to add an independent clause after it.
Fragment: After John ate breakfast
Sentence: After John ate breakfast, he walked to school.
Number 3 is the most common fragment mistake. Writers begin the sentence with a subordinate clause but forget to add an independent clause.
Remember: If you begin a sentence with a subordinate clause word, you need to put a comma after the subordinate clause and add an independent clause to finish the sentence.