Here are more words that business writers often confuse. Check your writing to be sure you don't fall into word confusion.
healthy; healthful. Traditionally, a living thing that is healthy enjoys good health; something that is healthful promotes health {a healthful diet will keep you healthy}. But healthy is gradually taking over both senses.
help (to). Omit the to when possible {talking will help resolve the problem}.
farther; further. The traditional distinction is to use farther for a physical distance {we drove farther north to see the autumn foliage} and further for a figurative distance {let's examine this further} {look no further}.
every day, adv.; everyday, adj. The first is adverbial; the second adjectival. One may wear one's everyday clothes every day.
stationary; stationery. Stationary describes a state of immobility or of staying in one place {if it's stationary, paint it}. Stationery denotes writing materials {love letters written on perfumed stationery}. To remember the two, try associating the er in stationery with the er in paper; or remember that a stationer is someone who sells letter paper.
determine whether; determine if. The first phrasing is irreproachable style; the second is acceptable, though less formal. The same is true of decide whether versus decide if.
toward; towards. The preferred form is without the s in American English, with it in British English. The same is true for other directional words, such as upward, downward, forward, and backward, as well as afterward. The use of afterwards and backwards as adverbs is neither rare nor incorrect. But for consistency, it is better to stay with the shorter forms.
who; whom. Here are the traditional rules: Who is a nominative pronoun used as (1) the subject of a finite verb {it was Jim who brought the coffee today}, or (2) a predicate nominative when it follows a linking verb {that's who}. Whom is an objective pronoun that may appear as (1) the object of a verb {I learned nothing about the man whom I saw}, or (2) the object of a preposition {the woman to whom I owe my life}. Today there are two countervailing trends: first, there's a decided tendency to use who colloquially in most contexts; second, among those insecure about their grammar, there's a tendency to overcorrect and use whom when who would be correct. Writers and editors of formal prose often resist the first of these; everyone should resist the second.
therefore; therefor. The words have different senses. Therefore, the common word, means "as a consequence; for that reason" {the evidence of guilt was slight; the jury therefore acquitted the defendant}. Therefor, a legalism, means "in return for" or "for it" {he brought the unworn shirt back to the store and received a refund therefor}.
it is I; it is me. Both are correct and acceptable. The first phrase is strictly grammatical (and stuffy); the second is idiomatic (and relaxed), often contracted to it's me. In the third-person constructions, however, a greater stringency holds sway in good English {this is he} {it isn't she who caused such misery}.
ingenious; ingenuous. These words are similar in form but not in meaning. Ingenious describes what is intelligent, clever, and original {an ingenious invention}. Ingenuous describes what is candid, naive, and without dissimulation {a hurtful but ingenuous observation}. The latter's opposite is disingenuous, describing what is lacking in candor or giving a false appearance of simple frankness.
idyllic. An idyll is a short pastoral poem, and by extension idyllic means "charming" or "picturesque." It is not synonymous with ideal (perfect).
gibe; jibe. A gibe is a biting insult or taunt; gibes are figuratively thrown at their target {the angry crowd hurled gibes as the suspect was led into the courthouse}. Jibe means "to fit or coincide" {the verdict didn't jibe with the judge's own view of the facts}. Don't confuse jibe with jive, which as a noun means "the jargon of hipsters" and as a verb means to "tease or cajole."
Source: The Chicago Manual of Style.
