Identifying a fragment is perhaps one of the most important steps when it comes to writing clearly and thoroughly. Give students worksheets with mixes of fragments and full sentences and ask them to decide which one is which. You can present it as a quiz, a simple in-class worksheet, a homework assignment, or a game. Divide your students into groups of four or five and challenge students to complete the work as quickly and accurately as possible. The first student group to finish with all of the correct answers "wins."
Write sentence fragments on the board and ask your students to fix the fragment in order to make it a sentence. Ask students to identify what is missing as a group so that those who may not understand do not feel confused. Have three or four students fix the fragment in order to make it a sentence so that students are aware that there may be several ways to fix a fragment. This activity can also be made into a game by challenging groups of three or four students to fix a fragment as quickly and accurately as possible.
If you are teaching older students who may still be struggling with the concept of complete sentences, ask them to write a short paragraph defining what they think a sentence is and which elements are necessary for one to be complete. Have students read their responses aloud and correct their definitions. Students should then rewrite their paragraphs according to the correct definition. Have students switch their papers with a partner and circle any sentence fragments they see.
The Internet is a powerful tool for education, and working on sentence fragments is no different. Many websites and online resources offer simple exercises that help students identify and fix sentence fragments in a fun, educational way. These activities are useful for home schooled students, assigning as homework, or for having students complete during a computer course, if your school offers one.