Comma Rules

Use comma to separate three or more items in a series

Use commas to show a pause after and introductory word and to set off names used in a direct address such as : Yes, most cities have few parking garages

Use a comma after two or more introductory prepositional phrases, when the phrase is very long, or when the comma is needed to make the meaning clear. A comma is not needed after a single, short prepositional phrase, but it is acceptable to use one in the example: In the fall of 1991, Frank M. Jordan was elected mayor. Where "In the fall" and "of 1991" are prepositional phrases

Use a comma after an introductory participial phrase, like in the example: Plagued by deficits, many cities need state aid.

Use commas to set off words to interrupt the flow of thought in a sentence like in the example: A large city, as you can see, employs many police officers

Use a comma after conjunctive adverbs such as however, moreover, furthermore, nevertheless, therefore. Such is shown in the example: The city is growing; therefore the city payroll must grow.

Use commas to set off an appositive if it is not essential to the meaning of the sentence

Use a comma before and, or, but when it joins the main clauses, such as in the example: Farming is a business, and farmers need to make a profit. Or with example 2: Farming can be rewarding, but it is hard work.

Use a comma after an introductory adverb clause. Adverb clauses begin with subordinating conjunctions, such as after, although, as, because, before, considering, if, in order that, since, so that, though, unless, until, when, whenever, where, wherever, where, whenever, whether, while. In the example: When the weather is too dry, farmers have problems. In the example, "farmers" is the subject and "have problems" is the main clause/simple sentence. In most cases, do not use a comma with an adverb clause that comes at the end of a sentence. This is shown again in a different example: Crops can be ruined if there is no rain.

Use a comma or a pair of commas to set off and adjective clause that is not essential to the meaning of a sentence. This means that the clause merely gives additional information. Adjective clauses often begin with the relative pronouns who, whom, whose, which or that. This is shown in the example: Dairy cows, which are common on farms, are raised for their milk. Do not use a comma or a pair of commas to set off and essential clause for the rest of the sentence. An adjective clause is essential when it is necessary to the meaning of the sentence, as shown in the example: An animal that is raised for milk is the dairy cow. The adjective clause is "that is raised for milk".

Use commas before and after the year, when it is used with both the month and the day. If only the month and the year are given, do not use a comma. This is shown in the following examples: The antipollution project began on May 25th, 1992, and lasted a year and: The first meeting was held in July 1992 and made headlines.

Use commas before and after the name of a state or a country when it is used with the name of the city. Do not use a comma after the state if it is used with a zip code. For example: The address on the envelope were as follows: 123 Ridge Road, CT 064777 and Speakers came from Palo Alto, California, to speak at the meeting.

Use a comma or pair of commas to set off an abbreviated title or degree following a person's name. For example: One expert on pollution and health is Jay Carr, M.D.

Use a comma or commas to set off too in the middle of a sentence, when too means "also". For example: Air pollution, too, creates problems and The courts, too, are involved

Use a comma, or commas, to set off a direct quotation. For example: Dr. Flores said, "Pollution is bad." and "We will try," said Joan, "To fight pollution."

Use a comma after the salutation of a friendly letter and after the closing of both a friendly letter and a business letter. Such as: Dear Sharon, Your Friend, Your Truly, Etc.

Use a comma for clarity in reading a sentence. For example: Instead of three, four people discussed pollution.