Sentence Structure

Simple, compound, and complex sentences; find the main clause of a long sentence to understand it; fix fragments and run-ons.

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 36

Welcome to Sentence Harbor! Sentences come in different shapes, like boats. Knowing the shape helps you read long sentences and write clear ones.
A simple sentence is one complete thought. It can still have two subjects or two verbs: Mia and Leo built a sandcastle.
A compound sentence joins two sentences with a comma and a word like and, but, or so. We wanted to swim, but the water was too cold.
A complex sentence has a main clause, which can stand alone, and a part that can't, starting with a word like when, because, or although.
In a long sentence, find the main clause first. It tells the main thing that happened: the captain slowed the boat. The other part tells when or why.
Watch out for fragments, which are missing part of the thought: Because the boat was leaking. And run-ons, which jam two sentences together: The storm was over we went back outside.
Fix a run-on with a period and a capital letter, or with a comma and a joining word. The storm was over, and we went back outside.

Georgia's K-12 English Language Arts Standards:

4.L.GC.2.a — Apply understandings of sentence structure to comprehend a wide variety of grade-level texts. (I)
4.L.GC.2.b — Use a variety of simple, compound, and complex sentences to strengthen clarity and coherence, maintaining consistent verb tense within and between paragraphs. (C)