Punctuation rules

- An introductory prepositional phrase defines the direction, time, location, or spatial relationship of the main clause. It is dependent on the main clause and cannot stand alone as a phrase. There must be a comma after the introductory prepositional phrase if it contains five or more words.

- However, if the introductory prepositional phrase contains four or fewer words, a comma is not necessary:

- There may be cases where a comma isn’t necessary but adds clarity to the phrase. In the phrase below, readers may think “night owls” is a single concept if the comma is excluded.

- An infinitive phrase starts with the infinitive form of a verb and is connected to a main clause.

- There are three possible grammatical patterns a sentence with an infinitive phrase may take. First is an introductory infinitive phrase that is followed by the main clause. This requires a comma after the introductory phrase.

- Secondly, an infinitive phrase may interrupt the main clause. In this case, commas are required to offset the infinitive phrase.

- The third pattern is when the infinitive phrase comes after the main clause. There is no need for punctuation between the two sentence parts.

A participle phrase begins with either a present or past tense participle. They always function as adjectives and add description to the phrase.

Present tense participles end in –ing:

While regular past tense participles end in –ed:

*It must be noted that irregular past tense participles will not follow a common form.

- When an introductory phrase begins with a subordinating conjunction (such as: even, as soon as, if, provided that, once), there is a comma after the introductory phrase. However, there is not a comma after the subordinating conjunction.

- An introductory phrase beginning with a subordinating conjunction is dependent on the main clause. Whether the dependent clause is before or after the main clause, the subordinating conjunction comes at the beginning of the dependent clause.

- Conjunctive adverbs 1) link two independent clauses in the same sentence, 2) link ideas in two or more sentences, and 3) show connections between ideas within a single independent clause.

- When a conjunctive adverb is used to link two independent clauses, it is preceded by a semicolon and followed by a comma.

- If a conjunctive adverb is used anywhere else in a phrase, it is off set by commas.

- An interjection conveys an emotion or feeling, and they are rarely seen in academic and formal writing. The interjection usually appears at the beginning of a sentence or clause with little connection to the rest of the phrase. They are most often followed by an exclamation point or comma.

- The interjection is followed by an exclamation point when it conveys very strong emotions like delight or surprise.

- In most other cases, the interjection is offset by commas. This includes when an interjection is found in the middle of a sentence.

Coordinating conjunctions connect items, phrases, or clauses. They are used to give equal weight to each phrase. Coordinating conjunctions are easily remembered with a simple acronym:

FANBOYS

- When a coordinating conjunction separates two main clauses or verbs, a comma precedes it. The second main clause needs to be an entirely independent clause, with a subject and verb, if you are to put a comma before the coordinating conjunction. Otherwise, don’t use the comma.

- Finally, when it is used to separate two items there is no punctuation.

When two independent clauses are not connected with a conjunction or another transitional expression, a semicolon is used to separate them. The semicolon works as a light period between the phrases; nonetheless, it keeps the two independent clauses in the same sentence. Both the independent clauses need to be able to operate as complete sentences if you are to use a semicolon.

- A non-restrictive clause provides non-essential information to the meaning of a sentence, and is offset by commas. It usually adds interesting information to the sentence, and it can be removed easily as well.

- The information here concerning where the sister lives is non-essential. The sentence makes just as much sense without it.

- The information offset by commas must be non-essential to understanding the phrase; if it’s essential information, do not use commas. For example, if the sister’s profession actually tells us which sister is helping, instead of just adding something of interest, it becomes essential information.

Question tags are placed at the end of statement in a way that transforms it into a question. They are often used when the speaker expects that the person with whom they’re speaking will agree with them, and they are used almost exclusively during informal interactions. Question tags are always separated from the main clause by a comma.

When a phrase contains a part that is in contrast with the subject, this part is offset by commas. Look for words like not, unlike, and never to signal a contrast to the subject.

- Commas are used only sometimes for dates, dependings on the information provided. When a phrase contains only the month and year, no punctuation is needed. These less-specific dates are also frequently preceded by "in."

- When the day of the month is also included, there must be a comma between the day and the year. These specific dates are frequently preceded by "on."

- Furthermore, if the day of the week is included, there is a comma after it.

- An appositive is a noun or a pronoun that is set next to another noun or pronoun and is used to describe or identify it.

- The appositive is offset by commas when the information is non-essential to understanding the phrase. If it’s essential information, do not use commas. For example, take the two sentences below:

- For example, if the sister’s profession actually tells us which sister is helping, instead of just adding something of interest, it becomes essential information.

- There must always be a comma before a direct quotation is inserted in a text.

- If there is an interruption in the quote, it i’s offset by commas. Following American grammar rules, the comma preceding the interruption is placed inside the quotation marks. However, this may vary depending on the country.

- If the quote is not from someone specific, but instead refers to a general statement do not include a comma.

- In this example, the speaker is not directly quoting someone, and is instead making a general statement. Furthermore, it isn’t an entrance to a dialogue.

You also don’t need a comma if you are not using a verb that introduces a direct quotation. While you will always need a comma after verbs like "said," "shouted," "scolded," and "pleaded," constructions like "she asked me to" and "he explained that" don’t take a comma before the quotation.

Lastly, Punctuation almost always goes inside the quotation marks.

The last example has the question mark outside the quotation because, while the quotation is a positive statement, it’s the sentence itself that is interrogative. The speaker wants to know if the person in question made a particular statement.

- "Et cetera" is Latin and is usually abbreviated as "etc." It’s used for two reasons: when the omitted material is obvious, and when additional information is unnecessary.

- When used at the end of a sentence, it is preceded by a comma and followed by a period.

- If the et cetera appears in the middle of a phrase it is followed by a period and a comma.

- Interrupters are small word group that convey tone, emotion, or emphasis in a sentence. They are offset with commas without commas the sentence flow would be awkward. Reading sentences aloud often helps determine if there is an interrupter or not.

There must be a comma before or after a name when it’s included at the beginning or end of a sentence.

- Coordinate, or paired, adjectives are two or more parallel adjectives used to modify a noun. Commas are used to separate these kinds of adjectives. There are ways to test whether or not the sentence contains coordinate adjectives.

- Firstly, sentences with coordinate adjectives still make sense if you replace the commas with the word and. If there are just two coordinate adjectives, separate them with the word and.

- This example shows that this phrase is, in fact, a series of coordinate adjectives:

- Secondly, if you can switch the order of the adjectives without compromising the meaning of the sentence, they are coordinate adjectives.

- On the other hand, adding the word and or changing the adjective order of noncoordinate adjectives confuses the meaning of the sentence. No commas are needed between this kind of adjective.

- Notice that if you change the order or add the word “and,” the sentence no longer makes sense.

- This shows that "red" and "sports" in the above sentence are not being used as coordinate adjectives.

- When putting an address in a sentence, each element is separated by a comma. The standard American address breaks down into these parts:

- In a sentence this address will contain a comma after the street number and street name, and after the city. If the sentence continues, there must also be a comma after the zip code.

- There are two ways to punctuate salutations at the start of a letter, depending on how formal it is. The general rule is to place a comma after the name; however, a semicolon may be used in formal writings instead.

- Commas are also inserted between a person’s name and post-nominal letters (academic degrees, certifications, affiliations, etc.). Keep in mind, there’s no comma between the abbreviations for junior or senior.

A letter closes with a complimentary closing followed by a comma (and usually a signature on the next line). The complimentary closing may be rather informal or very formal.

Correlative conjunctions connect two parallel items in a sentence. Pay careful attention to the fact that both parts of the sentence actually carry equal weight. Here are some common correlative conjunctions:

When the subject of a sentence is actually composed of two or more nouns or pronouns (e.g. Kate and Mike), there is no comma to separate the two. This is true whether the nouns are separated by the word and, or the word or.

Depending on the sentence surrounding the parentheses, there may either be one comma after the closing parentheses or none required. If the sentence doesn’t need a comma, once the parentheses are taken out, you should not add one. However, if there is a comma needed, it should be placed at the end of the parenthesis.

Nominal groups are word groups that provide information about people, places, and concepts. Also called noun phrases, nominal groups shouldn’t be split up by a comma because they will lose their meaning. You will need commas when there is a series of noun phrases in one sentence.

Example of a nominal phrase:

In the sentence above, there are three nominal groups in a series.

- When the phrase includes only two verbs, separate them by the word and, with out any punctuation. Commas are required after each verb in the series once the series includes three or more verbs. If there’s already a comma after each verb, use semicolons to separate each verb in the series.

- Two verbs in a series:

- Three or more in a series:

- A case with semicolons:

- In a series such as "cats, dogs, and elephants," the comma after "dogs" is called the "Serial" or "Oxford" comma. It makes sentences clearer, and is thus preferred in written English. You may see sentences without the final comma, however, and can choose to omit it and still have a grammatically correct sentence by writing "cats, dogs and elephants."

Commas shouldn’t be used in a comparison. Writers often place a comma after a conjunction in comparison phrases; however, this is incorrect.

- There are two places you will never, without exception, see commas. They should never separate the subject and the verb of a sentence, and should never be the start of a sentence. While commas are rarely mistakenly placed at the start of a sentence, we often see commas cropping up between the subject and the verb. This mistake frequently occurs when the subject clause is long or already has a verb in it.

- With the above sentence, you may be tempted to add a comma after "road"; however, this is incorrect. The verb of the sentence is to be and the subject is the way to check if you’re on the right road

- There should never be a comma after a conjunction that is followed by a phrase.