3rd Grade Sentence Structure Worksheets

Start with the concept that every sentence needs two things: someone or something (subject) and what they do or are (predicate). Use a simple framework: 'Who? Did what?' or 'What? Did what?' Build sentence awareness through oral language first — say a phrase ('under the table') and ask 'Is that a sentence? What's missing?' Then provide the missing part and have students form the complete sentence. Sentence combining is one of the most research-supported writing interventions. Give students two short sentences ('The dog is big. The dog is brown.') and model how to combine them ('The big, brown dog' or 'The dog is big and brown.'). Practice this daily with increasingly complex sentences. For run-on sentences and comma splices, teach students to identify where one complete thought ends and another begins. Mentor sentences — selecting one well-crafted sentence from a mentor text each week and studying its structure — is a powerful routine for upper grades. Have students imitate the pattern with their own content. When students write exclusively in simple sentences, challenge them to start sentences different ways: with a prepositional phrase (Under the bridge...), with an adverb (Carefully,...), or with a dependent clause (When the bell rang,...). Vary sentence length intentionally — short sentences create emphasis and tension, while longer ones add detail and flow.