Versus and vs.

This word is spelled out in prose but may be abbreviated to “vs.” in book, article, and presentation titles, in all levels of headings, and within tables (e.g., in a column head), figures (e.g., in a line label), and exhibits (e.g., in any entry). It is not abbreviated in the notes to figures, tables, or exhibits.

“Therefore,” “thus,” and other conjunctive adverbs

When “therefore,” “accordingly,” “nevertheless,” “consequently,” “thus,” “next,” and other such conjunctive adverbs begin a sentence, they are followed by a comma. Sometimes when they are in the middle of a sentence, they are functioning more as plain adverbs, to add emphasis, and you may or may not use commas around them. Omitting the commas is appropriate with the short adverbs: “thus,” “then,” “first,” “next.” When a longer pause in the sentence is desired, use a two (or more) syllable adverb (e.g., “therefore”) and use commas around it. When only a small break is desired, use the short form (e.g., “thus”) and no commas.

Examples: Accordingly, the profits rose.

Thus, the returns are abnormally skewed.

The returns, therefore, are abnormally skewed.

The returns are thus abnormally skewed.

The product has a peculiar sales pattern; thus, the returns are abnormally skewed.


“There” means “in that place” and shouldn’t be used as a lazy way to start a sentence. “There is/there are” constructions can almost always be stated more directly and concisely.

Example: “There are some occasions that require formal dress” is better as “Some occasions require formal dress.”

Singular vs. plural

Do not use “they” with a singular pronoun or noun, including a manager, a management, a board of directors, or a company.

Examples: an investment manager does not . . . but he or she may . . . .

IBM has no representatives . . . it does not want them

the board is voting on the question; it will report the vote tomorrow.

“The question is”

We use two forms for “the question is.” One form is to simply construct a declarative sentence (“The question is how long we should wait.”). Note that the sentence is declarative, so it ends with a period, with no comma after “is.” If you want to end with a question mark, set the sentence up in the second form, with a comma; capitalize the first letter of the question if it is a long question, such as eight words or more (“The question is, how long should we wait?”; “The question is, What should we do to avoid making this mistake in the future?”).

“Problematic” vs. “problem”

Careful writers do not consider “problematic” a synonym for “a problem.” “Problematic” means iffy, not definite or settled, open to question or debate. Avoid using it in the context of “is a problem.”

Examples: Whether we will find a solution is problematic [meaning questionable]. Finding a solution is a problem [meaning poses difficulties].

The phrase “a number”

According to Webster’s English Usage, “a number” always requires a plural verb because the meaning is plural: A number of employees have recently applied for dental coverage. But “the number” is singular: The number of employees who have dental coverage increases every year.


“Over” and “during” are not synonymous when used for time: “over this period” means from a point at the beginning of the time period to a point at the end of the time period; “during this period” means within the time period.

Example: During this period, prices fluctuated wildly, but the growth in the rate of return over the period was incredible.”

To check your use of the terms, try using “in” for “during” and “for” for “over.” (Sometimes, “in” and “for” may be used in place of “during” and “over.”)

Usage has made “over the long term” acceptable.


Consult the dictionary for plurals of Latin words (e.g., the word “data” is always plural) and note the exceptions to the dictionary in the Word List.

Examples: The data are incomplete. Data are…; data show; data dance; data sing.

The Latin abbreviations “etc.,” “i.e.,” and “e.g.” should only be used in parentheticals (in which case, they are followed by a comma); in text, they should be spelled out—using “and so on,” “that is,” and “for example,” respectively. If you use “e.g.” to introduce a list, do not use “etc.” at the end; it is redundant.

Use an English translation of “ceteris paribus,” which means “other things being equal” or “all else being equal.”

Most Latin terms are italicized; for example, use ex ante and ex post. Some terms and abbreviations (such as i.e., e.g., per se, and et al.), have become commonly accepted English terms, however, and should not be italicized.

Note: The term “et al.” in text or references is not preceded by a comma.