Grammar Rules for Comma

We often get confused in placing comma in the sentence. In such situation, either we put so many comma, or we leave it. Instead of misusing comma, you can stick with the basic rules which are mentioned below to avoid the confusion.

Now, what is a comma and why it is needed? The answer is:
Comma is a punctuation mark (,) used to indicate the separation of elements within the grammatical structure of sentence.
It indicates the pause which occurs while speaking. If a comma is omitted or misplaced, it can change the meaning of a sentence. 
Being a writer, I consider some basic rules to add comma in a right place. Those are:



Use comma with coordinate conjunction:

• Coordinating conjunctions are used to connect two independent clauses i.e (FANBOYS):
• for
• and
• nor
• but
• or
• yet
• so
• Comma is placed before coordinating conjunction between two independent clauses.
• We like to watch movies on the weekend, and we usually go for a walk in the park.
• Lily has quite less experience in writing, yet she is at senior designation in the company.

Note:

• Do not place comma before conjunction (and, but, or) if a sentence is formed of single subject  and two predicate unless the subject appears second time. 
• Do not place comma before conjunction (and) joining compound direct objects.

Use comma after introductory comment, word, clauses or phrase:

• Introductory clause/phrase comes before the main clause like-after, although, as, because, if, since, when, while
• To get first position in the class, you need to work hard in the exams.
• First, she should go for the blood tests.

Note: 

• Don't use comma after an independent clause when a dependent (subordinating) clause follows it.
• John came to know about his mistakes when he saw his test papers. (Correct)

Use comma when there is series of names, places, items etc:

• Mary, Lily and Ron are going to attend the party tonight.
• My favorite colors are red, lavender and blue.

Also, you can use comma-

1. To separate parenthetical expressions
• Expression that are not part of the main idea of the sentence (by the way, as a matter of fact, after all, well etc.)
• Elephant, as far as we know, is one of the most intelligent animal. 
2. In writing long numbers 
• John's current CTC is Rs. 4,00,000 p.a.
• If number is very long, then write it in words. For example- In 2010, ABC's turnover was US$ 5.5 billion. . 
3. When day and year come in a sentence 
• My date of birth is July 30, 1985. (Correct)
4. To separate city from state and state from the remaining sentence
• Cyrus lives in Mumbai, Maharashtra, since he got married.