Run-on sentences: use a full stop, not a comma

The rule

A comma alone can't join two complete sentences. Use a full stop (I was tired. I went to bed.) or a comma with and, but or so (I was tired, so I went to bed.), never I was tired, I went to bed.

Arabic often links ideas in one long sentence with و and ف, and many learners carry that habit into English with commas. In English, each complete idea with its own subject and verb needs a full stop or a joining word.

Examples

In a conversation

A: How was your day?

B: Long. I had two exams, so I'm really tired.

A: Did you eat?

B: Not yet. I'll cook something now.

Practice

Choose the best answer. The answers are at the end of the lesson.

1. Which sentence is correct?
   • a) I was hungry, I ate a sandwich.
   • b) I was hungry, so I ate a sandwich.
   • c) I was hungry I ate a sandwich.
2. We finished ___ went for a coffee.
   • a) early. We
   • b) early, we
   • c) early we
3. The test was ___ passed.
   • a) hard, however I
   • b) hard however I
   • c) hard. However, I

Tip

Test each comma: if a full sentence stands on both sides, use a full stop or add and, but or so. However starts a new sentence: It was raining. However, we went out. A semicolon also works, but a full stop is simpler.

Answers

1. b) I was hungry, so I ate a sandwich. A comma alone isn't enough; so joins the two sentences.
2. a) early. We. Two complete sentences need a full stop.
3. c) hard. However, I. However starts a new sentence and takes a comma.

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