Punctuation, Commas in English

 

When do we use commas?

ExplanationExamples
1. separate independent clauses

The following conjunctions (so-called coordinating conjunctions) are used in such case: *

and, but, for, nor, or, so, yet

The driver appealed against the parking ticket, but the judge did not grant it.
2.1. after introductory sub clausesIf you visit Paris, you will see the Eiffel Tower.
2.2. after introductory phrasesAs a matter of fact, I do know how to swim.
2.3. after introductory wordsMeanwhile, I was sitting at home waiting.
3.1. when sub clauses appear in the middle of the sentence.John, who was waiting in the car, phoned Susan.
3.2. when phrases appear in the middle of the sentence.I, as a can be expected, will pay for the damage.
3.3. when words appear in the middle of the sentence.We have, unfortunately, decided to dismiss you.
4. to set off three or more words, phrases or main clauses in a sentence.He opened the door, walked in, sat down, and switched on the television.
5. to set off two or more coordinate adjectives, that is, the meaning does not change when the order is altered.We had to stay in a number of cheap,uncomfortable,dirty hostels.
6. at the end of a sentence in order to indicate a pause.He was just dangerous, not evil.
7. to set off a nonrestrictive (also non-defining) relative clause. **Donald Trump, who was a failed casino owner, became US president in 2017.
8. when someone is addressed directly.Petra, can you help me with this please?
9. when a direct quotation is included.Descartes said,“I think, therefore I am.”
10. to show an appositive. ***Barack Obama, former US president, is still very popular in Europe.
11. in dates.Yes, July 20, 1969, was the date of the first moon landing.
12. separate identical words.By the time I thought of it, it was too late
13. in front of tag questions.You are German, aren’t you?
14. after digits indicating thousands.100,000
9,999,999
15.1. after a salutation in letters.Dear Susan,
15.2. after a farewell in letters.Yours faithfully,
  • * Note that ‘but’ and ‘and’ do not take a comma when both are relatively short.
  • ** restrictive relative clause= they tell us which person or thing, or which kind of person or thing, is meant;
    non-restrictive relative clause = they tell us more about a person or thing that is already identified.
  • *** When an appositive is only one word, no comma is needed.