English puctuation is quite often a personal matter and often varies from organisation to organisation, no matter whether that organisation is government-operated, company-operated, or an academic institution. Each organisation has its own 'house style', and whenever you have to write a lengthy article in English, you should make an effort to find out the 'house style' you need to follow. You will have some practice in the following weeks in gaining ideas on the general rules of English punctuation.
One of the most difficult aspects of English punctuation is knowing when to and not to use a comma. Here, we shall look at five major rules about commas, as well as seeing some examples: Rule 1: We use a comma after an introductory expression (that is, a word, phrase, or clause that comes before the subject and verb of the independent clause).
First, you must turn on the computer at the main switch.
When you finish your homework, you may go to the movies.
Rule 2: We use a comma to separate two independent clauses in a compound sentence when they are joined by and, but, or, or nor.
Jack and I were friends at school, but we haven't met for many years.
You can play tennis on that court over there, and Mary and I will play on this court.