where do we use (,)?

Use commas to separate words and word groups in a simple series of three or more items. My estate goes to my husband, son, daughter-in-law, and nephew. >Use a comma to separate two adjectives when the order of the adjectives is interchangeable. Example: He is a strong, healthy man. >If the subject does not appear in front of the second verb, a comma is generally unnecessary. Example: He thought quickly but still did not answer correctly. >When starting a sentence with a dependent clause, use a comma after it. Example: If you are not sure about this, let me know now. >A comma is usually unnecessary when the sentence starts with independent clause followed by a dependent clause. Example: Let me know now if you are not sure about this. >Use commas to set off nonessential words, clauses, and phrases (see Who, That, Which, Rule 2b). ete...