disinterested, uninterested Disinterested has two meanings: "unbiased" ("They chose a disinterested observer to serve as a judge") and "not interested" ("She seems completely disinterested in the whole idea"), which is also the basic meaning of uninterested. Though this second use of disinterested is common, it is often criticized, and uninterested can always be substituted. (来源：专业英语学习网站 http://www.EnglishCN.com)

due to When the due of due to is clearly an adjective ("absences due to the flu"), no one complains about the phrase. When due to is used as a preposition ("Due to the holiday, our office will be closed"), some people object, so in formal writing an alternative such as because of or owing to may be safer.

each Each presents several problems of agreement with verbs and pronouns. When the pronoun each is the subject, it normally takes a singular verb ("Each is unique"). When the adjective each modifies a singular noun subject, the singular verb is used ("Each car is equipped with radar"). Each of is followed by a plural noun or pronoun ("Each of the kittens was given to a different family," "Each of us asked one question"). When the adjective each follows a plural noun subject, a plural verb and plural pronoun commonly follow ("We each have our own concerns"). Each often takes a plural pronoun in reference, sometimes to avoid saying "his or her" ("Each person in the line had to show their ticket").

each other, one another The traditional rules call for each other to be used when referring to two ("The two girls looked at each other in surprise") and one another to be used when referring to three or more ("There will be time for people to talk with one another after the meeting"). In fact, however, they are employed interchangeably.

either Either as an adjective meaning "each (of two)" is still in common use ("a path lined with large trees on either side"). In either . . . or constructions, either should be placed where it will provide parallelism; thus, rather than "The gift will be donated either to the college or the public library" should ideally be rewritten as "The gift will be donated either to the college or to the public library" or "The gift will be donated to either the college or the public library." The verb following an either . . . or construction is normally singular ("Either the car or the truck is fine"). However, when both subjects are plural, or when the first is singular and the second is plural, a plural verb is expected ("Either Maria or her parents have the keys").

every Since every normally modifies a singular noun, a singular verb usually follows ("Every page contains important new information"). When every modifies two or more nouns joined by and, the singular verb is standard ("Every man, woman, and child is going to benefit"). Every is usually followed by a singular pronoun ("Every girl at the school knows she's got to do as well as the boys," "Every dish had its proper place on the shelf"). But it may also be followed by a plural pronoun; in particular, the plural pronoun is almost always used today when the gender of the subject is unknown or mixed ("Every student was asked to write their essay on something different").

good, well Both good and well are acceptable when used to express good health ("I feel good," "I feel well"), and good may also connote good spirits ("She felt good about her performance"). However, the adverb good has been much criticized, with people insisting that well be used instead ("The orchestra played well this evening"), and this adverbial use should be avoided in writing.

he, he or she It used to be standard to use he to mean "he or she" ("Today every customer thinks he can get a better deal somewhere else"). Today this is avoided, since it seems to ignore the existence of women. Since "he or she," when repeated within a sentence or paragraph, can easily sound awkward, writers can usually rewrite their sentences to avoid it: by putting the pronouns in the plural ("All students should hand in their papers by Friday"), by addressing the reader directly ("You should hand in your paper[s] by Friday"), or by removing the pronoun altogether, perhaps by using passive voice ("All papers should be handed in by Friday"). Similar methods can be done to avoid repeating him or her, his or her, and himself or herself.

hopefully When used to mean "I hope" or "We hope" ("Hopefully, they'll reach an agreement"), as opposed to "full of hope" ("waiting hopefully for good news"), hopefully is often criticized, even though other similar sentence adverbs (such as frankly, clearly, and interestingly) are accepted by everyone. Despite the objections, this sense of hopefully is now standard and can be used freely.

I, me In formal speech and writing, such phrases as "It's me," "Susan is taller than me," "He's as old as me," "Who, me?" and "Me too" are generally accepted. In formal writing, however, it is best to use I after forms of be ("It was I who discovered the mistake") and after as and than when the first term of the comparison is the sentence's subject ("The analysts knew less than I," "Almost any college graduate could do as well as I").

i.e., e.g. These two abbreviations are sometimes confused with each other. To avoid confusion, try to remember that i.e. stands for the Latin id est, meaning "that is," and e.g. stands for exempli gratia, or "for example." Both that is and i.e. typically introduce a rewording or clarification of an immediately preceding statement or word ("the country's largest industry—i.e., steel"). Both for example and e.g. introduce one or more examples that illustrate something just mentioned ("Let's consider some of the country's largest industries—e.g., oil, banking, and steel"). In American (but not British) writing, both i.e. and e.g. are normally followed by a comma.

if Both if and whether are commonly used with such verbs as doubt, see, ask, wonder, decide, and know to introduce a noun clause ("See if they have arrived," "He asked her whether she was feeling better"); both are acceptable even in formal contexts. The use of if to mean "though" ("an interesting if questionable idea") is also common and proper. If is often followed by a subjunctive verb, especially when the clause contains a condition that is clearly hypothetical or contrary to fact ("If we could foresee the future, life would be a lot easier"). The indicative is required when the clause is clearly not hypothetical ("If he knew those facts at the time, then he's guilty of lying").

impact Impact as a verb meaning "to have an impact" came into widespread use only in the 1980s, and it is still often criticized, though it remains common in business, journalism, and politics ("worried about how this would impact our sales"). In other writing, another verb such as affect, influence, impinge on, or hit can usually be substituted.

imply, infer Infer is mostly used to mean "to conclude" and is commonly followed by from ("I infer from your comments that . . ."). Imply is used to mean "to suggest" ("The letter implies that our service was not satisfactory"). The use of infer, with a personal subject, as a synonym of imply ("Are you inferring that I made a mistake?") is best avoided.

in, into The basic distinction between these two prepositions is clear: into is used with verbs of motion ("moving into the light," "backed into a parked car"), and in is used with verbs that show location ("found the letter in the folder," "hid it in the closet"). However, in is also used idiomatically with some verbs of motion ("the tree had been split in two," "told the kids to jump in the car"), and in some cases either one may be used ("put the names into [in] the hat," "don't go in [into] the kitchen yet"). In more formal writing, however, the traditional distinction is usually observed.

lay, lie Though these two words have long been used as synonyms, today they are usually distinguished, especially in writing. Lay is normally transitive ("He laid down the book"), and lie is normally intransitive ("She was lying on the bed"). But they are very easy to confuse, especially because of the similar forms of their past tenses (laid, lay) and past participles (laid, lain).