Printable Grade 3 Conjunctions Worksheet: Compound Sentences

Mastering the art of sentence combining is a foundational skill for third-grade writers. This worksheet helps students transition from simple sentences to fluid compound sentences by correctly applying conjunctions and commas. Students practice identifying the logical relationship between two main clauses and selecting the most appropriate coordinating conjunction to create a cohesive thought.

At a Glance

• Grade: 3 · Subject: English Language Arts
• Standard: CCSS.ELA-LITERACY.L.3.1.I — Produce compound sentences using coordinating conjunctions and correct comma placement.
• Skill Focus: Conjunctions and Compound Sentences
• Format: 3 pages · 9 problems · No answer key · PDF
• Best For: Independent grammar practice and homework
• Time: 15–20 minutes

What's Inside

This three-page resource features nine structured rewrite exercises. Each task provides two related sentences and a specific coordinating conjunction in brackets, such as "and," "but," or "or." A "Quick Tip" box on the first page reminds students to include a comma before the conjunction when joining main clauses, providing immediate instructional support.

Zero-Prep Workflow

This resource is designed for immediate classroom implementation. This zero-prep format also makes it an excellent choice for emergency sub plans.

• Print (30 seconds): Generate the three-page PDF and print enough copies for your small group or whole class.
• Distribute (1 minute): Hand out the worksheets and read the "Quick Tip" and examples aloud to ensure student clarity.
• Review (1 minute): Use the nine tasks as a quick check for understanding during a writing workshop.

Standards Alignment

The primary focus of this worksheet is `CCSS.ELA-LITERACY.L.3.1.I`: "Produce simple, compound, and complex sentences." Supporting this objective is `CCSS.ELA-LITERACY.L.3.1.H`, which requires students to use coordinating and subordinating conjunctions accurately. Both standard codes can be copied directly into lesson plans, IEP goals, or district curriculum mapping tools.

How to Use It

Assign this worksheet as a follow-up to a direct lesson on conjunctions to reinforce comma placement rules. During the activity, circulate and observe if students are consistently placing the comma before the conjunction; this serves as an excellent formative assessment for grammatical conventions. Most students will complete the nine tasks in approximately 15 to 20 minutes.

Who It's For

This resource is ideal for third-grade students developing their writing mechanics or older students requiring intervention in sentence structure. It pairs naturally with a short mentor text passage where students can highlight existing conjunctions before attempting to write their own compound sentences using the provided prompts.

According to EdReports 2024, high-quality instructional materials must provide explicit practice in sentence construction to bridge the gap between grammar knowledge and writing fluency. This worksheet addresses CCSS.ELA-LITERACY.L.3.1.I by requiring students to utilize coordinating conjunctions—specifically 'and,' 'but,' and 'or'—to synthesize two independent clauses into a single compound sentence. By focusing on the structural 'smoothness' of language through the application of commas and conjunctions, the resource supports the development of syntactic variety. This method aligns with evidence-based practices that move beyond isolated parts-of-speech identification toward active sentence manipulation. Educators can use these 9 targeted exercises to observe student mastery of comma placement before conjunctions, a critical milestone in third-grade conventions. The structured format ensures that students can independently apply these rules, fostering the writing stamina necessary for more complex narrative and informational tasks in later elementary grades.