When you join two complete sentences into a single sentence, you can use commas followed by a suitable connecting word: and, or, but, while or yet.
The comma is not required if the subject of the second part of the sentence is omitted or if the conjunction used is and or or.
 | The group members had to hand in their reports last week, but some were only submitted this week. |
The comma is not required if the subject of the second part of the sentence is omitted or if the conjunction used is and or or.
| The student had to hand in the work by Friday but didn’t make the deadline. |
| The student had to hand in the work by Friday or the work would receive a failing mark. |
Recommended citation:
«Joining sentences» [en línia]. A: Llibre d’estil de la Universitat de Barcelona. Barcelona: Universitat de Barcelona. Serveis Lingüístics. <https://www.ub.edu/llibre-estil/criteri.php?id=2315> [consulta: 21 novembre 2024].