If you are using a conjunction to connect only two items, it is incorrect to use a comma before the conjunction. In addition, if you are using a conjunction
If you are listing three or more items in a row, consider replacing all but the last of the conjunctions with a comma. Place ...
If you are trying to access a private calendar, please make sure you sign in with the same e-mail address (Windows Live ID) ...
If you are using "between" to associate two items, join the two items with "and," as in "between a rock and a hard place." ...
If you are using a conjunction such as "and" to connect two groups of words that have conflicting purposes, such as a question ...
If you are using a conjunction to connect only two items, it is incorrect to use a comma before the conjunction. In addition, ...
If you are using a noun that cannot be counted or divided, such as "oil," "happiness," and "furniture," it is incorrect to ...
If you are using a number to modify a noun, be sure the noun agrees with the number. Any number greater than one must modify ...
If you are using a singular noun to indicate possession, use an apostrophe before the "s." If you are using a plural noun, ...
If you are using more than one verb in your sentence, be sure all the verbs are either active (the subject performs the action, ...