Ordinal Numbers. Notice the form for second and third is d and not nd or rd.

For example:
Bjorn was given the 232d and 233d numbers our of 655.

Capitalize language and those school subjects followed by a number.

Do not capitalize general school subjects unless the subject is a language.

Languages: Arabic, English, Korean, Polish, and etc.

School Subjects: Biology 403, French, history, literature, Social Science 101, statistics, and etc.

When a subordinate clause introduces a complex sentence, it is usually followed by a comma unless it is very short.

For example:
When you come in the front door, make sure you push it shut, because the lock doesn't always catch.

Avoid putting the preposition at the end of a sentence.

Avoid: They were not sure which college they should apply to.
Better: They were not sure to which college they should apply.
(The preposition is now part of the phrase to which college.)

Avoid: Ask not whom the bell tolls for.
Better: Ask not for whom the bell tolls.

Common errors involve msiplacing the adverb only

The position of the adverb can affect the meaning of the sentence. The most common error involves misplacing the adverb only. Make sure that the adverb position conveys what you intend to say.

Example 1
Unclear: We only walked to the store and not to the bank.
(Did the speakers only walk and not run? Or did they walk only to the store and not elsewhere? The meaning is unclear.)
Clear: We walked only to the store and not to the bank.


Example 2
Unclear: She frequently calls the magazine editor. (Does she calls the magazine editor more frequently than she calls anyone else? Or does she simply call the editor many times [frequently]?)
Clear: She calls the magazine editor frequently.

Do not use would have in "if clauses" that express the earlier of two past actions. Use the past perfect.

Correct: If he had thought of it, he would have asked you to ride with us.
Incorrect: If he would have thought it, he would have asked you to ride with us.

Use the past perfect tense to refer to the event or action in the more distant past

When describing two events in the past that did not occur at the same time, use the past perfect tense to refer to the event or action in the more distant past.

Correct: I suddenly remembered that I had left my purse at the office.
Incorrect: I suddenly remembered that I left my purse at the office.

(Because leaving the purse at the office preceded remembering the fact, the past perfect form of had left should be used.)

Use a singular verb with sums of money or periods of time

Examples:
Ten dollars is a high price to pay.
Five years is the maximum sentence for that offense.

Use noon and midnight rather than 12:00 P.M. and 12:00 A.M.

Capitalize when two or more sentences follow a sentence ending with a colon

Example:
I love Mary's Writing: Her book, A Thousand Acres, was beautiful. Also, Moo was clever.

Capitalize English but do not capitalize math

Capitalize words derived from proper nouns.

Example:
I must take English and math.
English is capitalized because it comes from the proper noun English, but math does not come from mathland.

Do not capitalize little words within titles, e.g. prepositions.

Always capitalize the first and last words of titles of publications regardless of their parts of speech. Capitalize other words within titles, including the short verb forms Is, Are, and Be.

Exception: Do not capitalize little words within titles such as a, an, the, but, as, if, and, or, nor, or prepositions, regardless of their length.

Examples:
The Day of the Jackal
What Color Is Your Parachute?
A Tale of Two Cities

Some rules of how to use hyphens correctly

Rule (1) When adverbs other than -ly adverbs are used as compound words in front of a noun, hyphenate. When the combination of words is used after the noun, do not hyphenate.

Examples:
He got a much-needed haircut yesterday.
His haircut was much needed.

Rule (2) Hyphenate all compound numbers from twenty-one through ninety-nine.

Rule (3) Hyphenate all spelled-out fractions, e.g., one-third, and one-half.

Rule (4) Use the hyphen with prefix re only when: the re means again AND omitting the hyphen would cause confusion with another word.

Examples:
Will she recover from her illness?
I have re-covered the sofa twice.
Re does mean again AND omitting the hyphen would have caused confusion with another word.

Periods go inside parenthesis only if an entire sentence is inside the parenthesis.

Examples:
Please read the analysis (I enclosed it as Attachment A.).
OR
Please read the analysis. (I enclosed it as Attachment A.)

Use the semicolon before introductory words such as e.g., for example, or i.e., when they introduce a complete sentence.

Examples:
You will want to bring many backpacking items; for example, sleeping bags, pans, and warm clothing will make the trip better.

If the phrase has fewer than three words, the comma is optional.

Use a comma after the phrase of more than three words that begin a sentence. If the phrase has fewer than three words, the comma is optional.

Examples:

On February 14, many couples give each other candy or flowers.

OR

On February 14 many couples give each other candy or flowers.

The day of the month

Use a common to separate the day of the month from the year and after the year.

Example: Kathleen met her husband on December 6, 2003, in New York, NY.

If any part of the date is omitted, leave out the comma.

Example: They met in December 2003 in New York, NY.

Different from vs Differently than

Rule: Use different from, not different than.

Example: The weather was different from what we expected.

You may use differently than when a clause precedes and follows the expression.

Example: He works differently than she does.

Like vs As if

The word like when used to show comparison, is a preposition, meaning that it should be followed by an object of the preposition but not by a subject and verb. Use as or as if when following a comparison with a subject and verb.

Examples:

You look so much like your mother.
Mother is the object of the preposition like.

You look as if you are angry.
As if is connecting two pairs of subjects and verbs.