Major rules of using comma, semicolon and colon in English

12 Rules For Using Commas Without Looking Like An Idiot

1. Use a comma before any coordinating conjunction (and, but, for, or, nor, so, yet) that links two independent clauses.

Example: "I went running, and I saw a duck."

You may need to learn a few grammatical terms to understand this one.

An independent clause is a unit of grammatical organization that includes both a subject and verb and can stand on its own as a sentence. In the previous example, "I went running" and "I saw a duck" are both independent clauses, and "and" is the coordinating conjunction that connects them.

 Consequently, we insert a comma.

If we were to eliminate the second "I" from that example, the second clause would lack a subject, making it not a clause at all. In that case, it would no longer need a comma: "I went running and saw a duck."

2. Use a comma after a dependent clause that starts a sentence.

Example: "When I went running, I saw a duck."

A dependent clause is a grammatical unit that contains both subject and verb but cannot stand on its own, like "When I went running ..."

Commas always follow these clauses at the start of a sentence. If a dependent clause ends the sentence, however, it no longer requires a comma. Only use a comma to separate a dependent clause at the end of a sentence for added emphasis, usually when negation occurs.

3. Use commas to separate appositives from the rest of the sentence.

Appositives act as synonyms for a juxtaposed word or phrase. For example, "While running, I saw a mallard, a kind of duck." "A kind of duck" is the appositive, which gives more information about "a mallard."

If the appositive occurs in the middle of the sentence, both sides of the phrase need a comma. As in, "A mallard, a kind of duck, attacked me."

"A mallard, the kind of duck I saw when I went running, attacked me."

4. Use commas to separate items in a series.

For example, "I saw a duck, a magician, and a liquor store when I went running."

That last comma, known as the serial comma, Oxford comma, or Harvard comma, causes serious controversy. Although many consider it unnecessary, others, including Business Insider, insist on its use to reduce ambiguity.

5. Use a comma after introductory adverbs.

"Finally, I went running."                                    

"Unsurprisingly, I saw a duck when I went running."

Many adverbs end in "ly" and answer the question "how?" How did someone do something? How did something happen? Adverbs that don't end in "ly," such as "when" or "while," usually introduce a dependent clause, which rule number two in this post already covered.

6. Use a comma when attributing quotes.

The rule for where the comma goes, however, depends on where attribution comes.

If attribution comes before the quote, place the comma outside the quotations marks. The runner said, "I saw a duck."

If attribution comes after the quote, put the comma inside the quotation marks. "I saw a duck," said the runner.

7. Use a comma to separate each element in an address. Also use a comma after a city-state combination within a sentence.

"I work at 257 Park Ave. South, New York, N.Y. 10010."

"Cleveland, Ohio, is a great city." 

8. Also use a comma to separate the elements in a full date (weekday, month and day, and year). Also separate a combination of those elements from the rest of the sentence with commas.

"March 15, 2013, was a strange day." Even if you add a weekday, keep the comma after "2013."

"Friday, March 15, 2013, was a strange day."

"Friday, March 15, was a strange day."

You don't need to add a comma when the sentence mentions only the month and year. "March 2013 was a strange month."

9. Use a comma when the first word of the sentence is freestanding "yes" or "no."

"Yes, I saw a duck when I went running."

"No, the duck didn't bite me."

10. Use a comma when directly addressing someone or something in a sentence.

My editor often asks, "Christina, is that article up yet?"

Another clever meme shows the problem with incorrect placement of this comma. "Stop clubbing baby seals" reads like an order to desist harming infant mammals of the seal variety. The version with a comma, however, instructs them to stop attending hip dance clubs. "Stop clubbing, baby seals."

11. Use a comma between two adjectives that modify the same noun.

For example: "I saw the big, mean duck when I went running."

Only coordinate adjectives require a comma between them. Two adjectives are coordinate if you can answer yes to both of these questions: 1. Does the sentence still make sense if you reverse the order of the words? 2. Does the sentence still make sense if you insert "and" between the words?

Since "I saw the mean, big duck " and "I saw the big and mean duck" both sound fine, you need the comma.

Sentences with non-coordinate adjectives, however, don't require a comma. For example, "I lay under the powerful summer sun." "Powerful" describes "summer sun" as a whole phrase. This often occurs with adjunct nouns, a phrase where a noun acts as an adjective describing another noun — like "chicken soup" or "dance club."

12. Use a comma to separate negation in a sentence.

For example: "I saw a duck, not a baby seal, when I went running."

In this case, you still need the comma if the negation occurs at the end of the sentence. "I saw a baby seal, not a duck."

Also use commas when any distinct shift occurs in the sentence or thought process. "The cloud looked like an animal, perhaps a baby seal."

How to Use a Semicolon Correctly

The most common use of the semicolon is to join two independent clauses without using a conjunction like and.

Do you use a capital letter after a semicolon? The general answer is no. A semicolon should be followed by a capital letter only if the word is a proper noun or an acronym.

We can go to the museum to do some research; Mondays are pretty quiet there.

Remember, semicolons are not interchangeable with commas or periods. Instead, they’re somewhere in between: stronger than a comma but not quite as divisive as a period.

1. Semicolons Connect Related Independent Clauses

You can use a semicolon to join two closely related independent clauses. Let’s put that another way. The group of words that comes before the semicolon should form a complete sentence, the group of words that comes after the semicolon should form a complete sentence, and the two sentences should share a close, logical connection:

I ordered a cheeseburger for lunch; life’s too short for counting calories.

Money is the root of all evil; I don’t believe the reverse is necessarily true.

Martha has gone to the library; Andrew has gone to play soccer.

Notice that the letter following the semicolon is not capitalized. The examples above are both made up of two complete, grammatically correct sentences glued together. Yes, that means there are four total sentences up there—and thanks to the semicolon, only two capital letters. That’s exactly why you can’t substitute a comma for a semicolon. Using a comma instead of a semicolon in the sentences above would result in a comma splice. And there’s nothing as painful as a comma splice.

2. Delete the Conjunction When You Use a Semicolon

A semicolon isn’t the only thing that can link two independent clauses. Conjunctions (that’s your and, but, and or) can do that too. But you shouldn’t use a semicolon and a conjunction. That means when you use a semicolon, you use it instead of the and, but, and or; you don’t need both. Here’s a hint: if you used a comma and an “and” to link two related ideas, think of the period (you know, the top part of the semicolon) as a replacement “and.”

I saw a magnificent albatross, and it was eating a mouse.

I saw a magnificent albatross; it was eating a mouse.

You need a comma plus something to avoid a comma splice. That something can either be the right conjunction or the period that turns a comma into a semicolon. If semicolons can link independent clauses that would otherwise have a period or a conjunction between them, that means they can demonstrate contrast, too. This is part of the same rule, but the conjunction in question is “but” instead of “and.” In other words:

This is part of the same rule; the conjunction in question is “but” instead of “and.”

To summarize, a semicolon links up two related ideas by narrowing the gap between the ideas of two separate sentences or by replacing a conjunction between two related ideas. That goes for showing contrast, too: just because two ideas are opposed or contradictory, that doesn’t mean they aren’t related closely enough to earn themselves a semicolon.

3. Use Semicolons in a Serial List

You can use semicolons to divide the items of a list if the items are long or contain internal punctuation. In these cases, the semicolon helps readers keep track of the divisions between the items.

I need the weather statistics for the following cities: London, England; London, Ontario; Paris, France; Paris, Ontario; Perth, Scotland; Perth, Ontario.

My plan included taking him to a nice—though not necessarily expensive—dinner; going to the park to look at the stars, which, by the way, are amazing this time of year; and serenading him with my accordion.

Let’s recap: so far we’ve got semicolons for linking two independent clauses; replacing a conjunction (whether showing similarity, like “and,” or opposition, like “but”); and long, comma-loving lists. Yup, that was one now.

4. Use Semicolons With Conjunctive Adverbs

When you have a conjunctive adverb linking two independent clauses, you should use a semicolon. Some common conjunctive adverbs include moreover, nevertheless, however, otherwise, therefore, then, finally, likewise, and consequently. 

I needed to go for a walk and get some fresh air; also, I needed to buy milk.

Reports of the damage caused by the hurricane were greatly exaggerated; indeed, the storm was not a “hurricane” at all.

The students had been advised against walking alone at night; however, Cathy decided walking wasn’t dangerous if it was early in the evening.

I’m not all that fond of the colors of tiger lilies; moreover, they don’t smell very good.

These words sometimes show up in other parts of a sentence; therefore, the semicolon rule only applies if it helps the conjunctive adverb join two independent clauses. (See what we did there?) This conjunctive adverb rule is similar to the conjunction rule. In both cases, check that the two ideas are independent clauses that could stand on their own as sentences. If so, then you’re grammatically good to go as far as the semicolon is concerned.

5. Use a Semicolon to Give a Wily Wink

Emoticons will never replace a solid knowledge of the English language. But they can sure spice it up from time to time. 😉 The semicolon is a good punctuation mark to have in your back pocket. Or on top of your parenthetical smile. So whether you’re using it to whip up a good complex sentence or to give someone a wink, now you know how to do it right.

5 Rules of Colon Usage

Colons can be confusing, that's true, but their function is actually quite straightforward: they introduce related information. Learning how to use colons correctly, along with other punctuation rules, can give your writing more clarity.

Without knowing how to effectively use colons, a writer can end up just putting colons everywhere, nowhere at all, or interchanging the colon with a semicolon or comma. To avoid precisely that, let's take a look at these 5 rules of colon usage.

5 Rules of Colon Usage

There are five key rules for colon usage that should always be followed:

1. Use a colon to introduce an item or list, if the list comes after a complete sentence or independent clause. For example:

·         There are three things every dog needs: food, water, and healthcare.

·         This year I want to visit four amazing cities: Paris, London, New York, and Barcelona.

2. Use colons between two sentences if the second sentence emphasizes or illustrates the first. For example:

Thinking back, our trip to Ireland was the best: we saw some of the most beautiful terrain this earth has to offer.

Traditionally, you had to capitalize the first word after a colon when the colon introduced a complete sentence, but that has become a style choice more than a rule.

3. Use a colon to introduce a bulleted or numbered list. For example:

The English language is spectacular. There are 14 different types of punctuation marks:

·         Periods

·         Question Marks

·         Exclamation Points

·         Commas

·         Semicolons

·         Colons

·         Dashes

·         Hyphens

·         Brackets

·         Braces

·         Parentheses

·         Apostrophes

·         Quotation Marks

·         Ellipses

Note: capitalization and ending punctuation are optional for single words or short phrases in bullet points or numbered lists.

4. Use a colon to introduce extended quotations. You should not use quotation marks and you should single space the quotation and indent from the left margin. For example:

Dyer's philosophy can be summed up in his belief that our thoughts manifest our reality:

Act as if what you intend to manifest in life is already a reality. Eliminate thoughts of conditions, limitations, or the possibility of it not manifesting. If left undisturbed in your mind and in the mind of intention simultaneously, it will germinate in the physical world.

5. Use a colon following a greeting (also known as a salutation) in a formal or business letter. It does not matter if you are using the person's first name, both first and last name, or their title, you should always use a colon if the letter is formal. If the letter is personal, then either a colon or comma is appropriate.

·         To Whom It May Concern:

·         Dear Mr. Wilson: