Writing · Commas
Combine each pair of sentences into one sentence, following the direction in parentheses. Use a comma after the introductory element. You can add, delete or rearrange words as needed.
Example: Students watch English movies. They improve their listening skills. (Begin with by watching.)
Answer: By watching English movies, students improve their listening skills.
Your sentence is compared with a model answer. If yours is different but uses the comma correctly, click Show Answer to compare.
About This Rule
- Use a comma after an introductory element, the words that come before the main clause of a sentence.
- This includes introductory clauses (Although students make mistakes, they learn from them.), -ing phrases (By reading books in English, students learn new vocabulary.) and longer prepositional phrases (In addition to teaching classes, professors mentor students.).
- After a very short introductory phrase, the comma is sometimes optional, but after an introductory clause it is always recommended.