Run-on sentences and comma splices

Start with "The test was hard, I passed." Each fix is correct; choose the one that shows the link you mean.

Words such as however, therefore, moreover and for example are adverbs, not joining words. A comma before them still leaves a comma splice: "Prices rose, however, demand stayed high" is wrong.

Use a full stop or a semicolon before them: "Prices rose; however, demand stayed high." Another option is to make one clause dependent: "Although prices rose, demand stayed high."

• Wrong: Many people own cars, this causes pollution.

  Right: Many people own cars, and this causes pollution.

  Two independent clauses joined only by a comma make a comma splice.

• Wrong: The rent is high, therefore many students live at home.

  Right: The rent is high; therefore, many students live at home.

  Therefore is not a joining word. Use a semicolon or a full stop before it.

• Wrong: My sister is a doctor she works in Leicester.

  Right: My sister is a doctor. She works in Leicester.

  A fused sentence has nothing between the two clauses.

• Wrong: Online classes are flexible, for example students can study at night.

  Right: Online classes are flexible. For example, students can study at night.

  For example doesn't join clauses, so start a new sentence.

Comma splices are one of the most common errors in IELTS and PTE essays, especially around however and therefore. The public IELTS descriptors refer to the frequency of errors, so a splice repeated in every paragraph adds up. When you review your essay, check each comma: if there is a full sentence on both sides, it needs a joining word, a semicolon or a full stop.

Try each one, then open it to check your answer.

1. 1. Run-on or correct? "I was tired, so I went to bed."

   Correct.

   The comma is followed by the joining word so.

2. 2. Fix with a semicolon: "The shop was empty, the staff had left."

   The shop was empty; the staff had left.

   A semicolon can join two closely related clauses.

3. 3. Fused sentence or comma splice? "It is cold outside wear a coat."

   Fused sentence.

   There is no punctuation between the clauses at all.

4. 4. Correct this: "The plan is cheap, however, it is slow."

   The plan is cheap; however, it is slow.

   However needs a semicolon or full stop before it when it starts a new clause.

5. 5. Fix with a dependent clause: "She was nervous, she gave a great speech."

   Although she was nervous, she gave a great speech.

   Although makes the first clause dependent, so the comma is now correct.

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