4    a/an and one

A.    a/an and one (adjective)

1.     When counting or measuring time, distance, weight etc we can use either a/an or one for the singular:

£1 = a/one pound      £1,000,000 = a/one million pounds (See chapter 36.)

But note that in The rent is £100 a week the a before week is not replaceable by one.

In other types of statement a/an and one are not normally interchangeable, because one + noun normally means 'one only/not more than one' and a/an does not mean this

A shotgun is no good (It is the wrong sort of thing )

One shotgun is no good (I need two or three )

2.     Special uses of one

(a)  one (adjective/pronoun) used with another/others

One (boy) wanted to read, another/others wanted to watch TV

(See 53 )

One day he wanted his lunch early, another day he wanted it late

(b)  one can be used before day/week/month/year/summer/winter etc  or before the name of the day or month to denote a particular time when something happened

One night there was a terrible storm One winter the snow fell early One day a telegram arrived

(c)  one day can also be used to mean 'at some future date'.

One day you 'II be sorry you treated him so badly (Some day would also be possible ) (For one and you, see 68 )

B.     a/an and one (pronoun)

one is the pronoun equivalent of a/an

Did you get a ticket? ~ Yes, I managed to get one The plural of one used in this way is some

Did you get tickets? ~ Yes, I managed to get some