Common Problems to Avoid
That and which: If the clause is essential to the meaning of the sentence, it takes that without commas: the entrance that we came through. If the clause can be omitted without changing meaning, it takes which and commas: The entrance, which is to the left of the parking lot, has a red door.
Comma with appositives: If an appositive is the only one in its category, it takes a comma (his wife, Mary; her first book, A Shady Tale). If there are or may be others in the category, a comma is not used (his sister Mary).
No colon before list: Verbs or prepositions introducing lists do not require colons (including Joe, Mary, and Ted instead of including: Joe, Mary, and Ted).
Commas with compounds: A compound sentence with two or more independent clauses requires a comma. (Bill went to pick up the hors d’oeuvres, and Sue made sure that the name cards were in the correct places on the tables.) A sentence with two or more clauses that have the same subject does not take a comma. (Bill went to pick up the hors d’oeuvres but turned around when he realized he'd forgotten his wallet.)
X ray, X-ray: The noun doesn't have a hyphen, the adjective does. In scientific usage, x ray is often lowercased.
Comma following the year in a date: When a month, date, and year are given, a comma must be used after the year as well as before it (the May 24, 2009, deadline). If only the month and year are given, no comma is used.
Comma following a state name: When a city and state are given, a comma must be used after the state as well as before it (Wilmette, Illinois, to the north).
Punctuation with quotes: Commas and periods go inside quotation marks; the context determines the placement of other punctuation marks.
Course work: Two words.
Quality: Should not be used as an adjective without a modifier (high-quality work, not quality work).
Freshman, freshmen: The adjective is freshman, not freshmen (freshman applicants).
Under way: Two words.
Individual, individuals: Avoid using as a noun; use “a person” or “people.”
Very: Is very overused. It’s a good practice to search for and delete it where possible.
Bad line breaks: Software programs may incorrectly hyphenate some words, such as academic (should be aca-dem-ic), and may not distinguish between a verb (pro-ject) and a noun form (proj-ect).
Small caps: If setting type that would normally be upper- and lowercase in small caps, check to make sure that large caps are used for capital letters.