adj.1. Being a single entity, unit, object, or living being: I ate one peach.
2. Characterized by unity; undivided: They spoke with one voice.
3. a. Of the same kind or quality: two animals of one species.
b. Forming a single entity of two or more components: three chemicals combining into one solution.
4. Being a single member or element of a group, category, or kind: I'm just one player on the team.
5. Being a single thing in contrast with or relation to another or others of its kind: One day is just like the next.
6. Occurring or existing as something indefinite, as in time or position: He will come one day.
7. Occurring or existing as something particular but unspecified, as in time past: late one evening.
8. Informal Used as an intensive: That is one fine dog.
9. Being the only individual of a specified or implied kind: the one person I could marry; the one horse that can win this race.
Usage Note: In formal usage, the pronoun
one is sometimes used as a generic pronoun meaning "anyone":
One would hope that train service could be improved. The informal counterpart of
one is
you: You never know what to expect from her. Trouble arises when
one is used in a series of sentences, and there is a need for a relative pronoun to refer back to
one. One option is to use
one and
one's repeatedly, as in
One tries to be careful about where one invests one's money. But in a sequence of sentences this inevitably becomes tedious. A traditional alternative has been to use
he, him, and
his: One tries to be careful about his investments. This has the drawback of raising the specter of gender bias. Because of these problems, the temptation may arise to switch to
you, but this will undoubtedly be distracting to the reader. It is better to use the same generic pronoun throughout. · As a generic pronoun,
one should be avoided as the direct object of a verb or a preposition, especially if it comes at the end of the sentence. Thus the sentence
Bad dreams can make one restless may sound stilted, but
One must not tease the bears or they will attack one sounds almost ungrammatical. As a subject or in the possessive form,
one fares much better.
One should be cordial with one's colleagues sounds somewhat formal, but is acceptable. · Does the phrase
One of x, where
x is a plural noun phrase, take a singular or a plural verb? Sometimes the answer is straightforward. In the sentence
One of every ten rotors was found defective, the one defective rotor is contrasted with, rather than being an example of, the larger group of rotors. A singular verb is almost always used here because it agrees with the singular "one." In 2001, 99 percent of the Usage Panel accepted the singular verb in this sentence. In many cases, the contrastive use of
one of can be easily identified by the fact that the phrase containing
one is introduced by the definite article:
He is the only one of the students who has (not
have)
already taken Latin. Constructions such as
one of those people who are more problematic. In the sentence
He is one of those men who are constantly complaining about their jobs, the one man, rather than being in contrast to the larger group, is an example of a larger group of men who complain. The relative pronoun
who appears to refer to
men, and so the verb should be plural:
are. But the use of a singular verb in sentences like these has long been common, even among the best writers, presumably because the relative clause, though semantically modifying the adjacent noun (
men), feels like it fits equally well with the subject noun (
he). The Usage Panel, accordingly, does not have a strict preference for the plural form. In our 2014 survey, although 72 percent accepted the plural
are constantly complaining, 57 percent accepted the singular
is constantly complaining. In some cases the Panel actually preferred the supposedly incorrect singular: 64 percent accepted
The sports car turned out to be one of the most successful products that was ever manufactured in this country, while only 55 percent accepted
were ever manufactured. Several Panelists commented that they decide by ear which verb form to use, and that appears to be the most viable advice. In some (but not all) cases, the sentence can be rewritten to avoid the choice:
The sports car turned out to be one of the most successful products ever manufactured in this country. · Constructions using
one or more or
one or two always take a plural verb:
One or more cars were parked in front of the house each day this week. One or two students from our department have won prizes. Note that when followed by a fraction,
one ordinarily gets a plural verb:
One and a half years have passed since I last saw her. The fraction rule has an exception in that amounts are sometimes treated as singular entities:
One and a half cups is enough sugar. Note also that the plural rule does not apply to these one-plus-a-fraction constructions that are introduced by the indefinite article. These constructions are always singular:
A year and a half has passed since I last saw her. See Usage Note at
he1.