When should I use a comma in a sentence.
http://grammar.ccc.commnet.edu/grammar/commas.htm
There are several reasons. Study the categories here, and post sentences you have questions about.
To determine when to use a comma in a sentence, there are several common rules and guidelines to consider. Here are a few of the most important instances:
1. Use a comma to separate items in a series: When you have a list of three or more items, separate them with commas. For example: "I bought apples, oranges, and bananas." The comma before "and" helps to clarify the individual items in the list.
2. Use a comma to separate introductory elements: When a sentence begins with an introductory word, phrase, or clause, it should be followed by a comma. For example: "However, I decided to go anyway." The comma comes after the introductory word "However" to signal the beginning of the main sentence.
3. Use a comma to set off nonessential information: When you have a word or phrase that provides additional, nonessential information in the middle of a sentence, it should be set off by commas. For example: "John, who is my neighbor, invited me to his party." The words "who is my neighbor" provide extra information about John but can be removed without changing the essential meaning of the sentence.
4. Use a comma before coordinating conjunctions: When you have two independent clauses (complete sentences) joined by coordinating conjunctions (such as "and," "but," "or," "so," etc.), use a comma before the conjunction. For example: "I went to the store, and I bought some groceries." The comma before "and" helps to show the separation between the two independent clauses.
It's important to note that these guidelines are not exhaustive, and there may be other specific situations that require the use of a comma. Additionally, style guides can vary, so it's always a good idea to consult the appropriate style guide (such as APA or MLA) for any specific rules related to your writing context.