Please do not make the following common errors (for a complete list, please see http://www.wsu.edu/
~brians/errors/errors.html):
Possessive Pronouns it its (not it's, a contraction of it is; note: there is no such word as its') you your (not you're, a contraction of you are) they their (not they're, a contraction of they are) who whose (not who's, a contraction of who is)
Other Common Errors everyday (adjective) vs. every day (noun) lead (present tense) vs. led (past tense) irregardless is not a word, don't use it
then (adverb) vs. than (conjunction) lose (verb) vs. loose (mainly an adjective) data is the plural of datum
e.g., (for example) vs. i.e., (that is)
"This applies to universities in the DC Metro Area (e.g., The Johns Hopkins University)."
"This refers to the best business school in the DC Metro Area (i.e., The Johns Hopkins University)." that vs. which
Restrictive (identifying) clauses use that and are not set off with commas:
BU.350.620 is the course that I take on Mondays.
Non-restrictive (commenting) clauses use which and are set off with commas or parentheses:
BU.350.620, which is a Carey required course, is the course I take on Mondays.
Comma preceding and
It is correct to have a ',' precede 'and' in a list of words that denotes a separation of the items as distinct as shown below:
"The budget is split between Chris, Dan and Al."
Meaning: Chris gets 50%, Dan and Al each get 25%
"The budget is split between Chris, Dan, and Al."
Meaning: Each gets 1/3