C Curriculum Explorer
English·Grammar & Punctuation·procedural

Commas Before Joining Words

Use a comma before a coordinating conjunction (and, but, or, so, yet) when joining two independent clauses in a compound sentence

Suggested ages 9–11

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Learning journey

Your child is mastering advanced grammar and punctuation — using complex sentence structures with relative clauses, understanding how to change word meanings with prefixes and suffixes, and creating cohesive, well-connected writing.

Evidence of understanding

  • Place a comma before the coordinating conjunction in a compound sentence, e.g. 'I wanted to go outside, but it was raining'
  • Distinguish compound sentences (two independent clauses) from simple sentences with compound predicates, e.g. 'She sang and danced' needs no comma but 'She sang a song, and he played the piano' does
  • Edit writing to insert missing commas before coordinating conjunctions in compound sentences

Assessment prompt

When Commas Before Joining Words joins two complete thoughts with a word like "but" or "so" — like "I wanted to go, but it was raining" — do they put a comma before that joining word?

Standards alignment

L.4.2cUS · ccss-ela

L.4.2c

Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects · 4

L.5.2bUS · ccss-ela

L.5.2b

Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects · 5