Skip to main content

GuideGrammarMixed10 min

Control Complete Sentence Boundaries

Fragments, run-ons, and comma splices

What you'll learn

  • Fragments, run-ons, and comma splices

How it works

A complete independent clause expresses a subject and a finished verb relationship. Two independent clauses need a period, semicolon, or coordinating/subordinating structure; a comma alone is not enough. A dependent clause beginning with because, although, when, or if cannot usually stand alone. Boundary control matters because readers must see where one claim ends and the next relationship begins. During revision, underline each finite verb and identify which clause it belongs to before changing punctuation.

Patterns

  • Coordination

    Independent clause, and/but/so independent clause.

    Connect equally important complete ideas while naming their relationship.

  • Subordination

    Although/Because/When dependent clause, independent clause.

    Make one idea the context, cause, time, or limitation of another.

Before and after

  • Before
    The venue changed, I cannot attend the stairs-only room.
    After
    The venue changed, so I cannot attend the stairs-only room.
    Why
    So turns the comma splice into a cause-result relationship.
  • Before
    Because the first shuttle arrives after orientation.
    After
    Because the first shuttle arrives after orientation, I need a later briefing.
    Why
    The dependent reason now has an independent result.

Practice

  1. Separate two run-ons using different methods.
  2. Complete three because-fragments with meaningful results.
  3. Audit one paragraph by marking every independent clause.
Show the answer key
  1. Accept period, semicolon, or accurate coordinator for each run-on.
  2. Every because clause must connect to a complete main idea.
  3. Each independent clause should have a clear subject-verb relationship.

What's next

Apply this strategy in scored practice, or continue with the next lesson.

Independent CELPIP-style practice material. This is not an official CELPIP question.

Control Complete Sentence Boundaries · TestCELPIP