One / ones

Avoiding repetition

1. One and ones

One is a pronoun used to replace a singular countable noun, so as to avoid unnecessary repetition.

IMG UNIT 13-01
- I've bought these two lipsticks.
IMG UNIT 13-02
- I like both but the purple one is gorgeous.

However, we will use ones to replace plural countable nouns.

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- Whose are these socks?
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- The big ones are mine.

2. How are one and ones used?

These particles are used according to specific structures:

WHICH ONE
IMG UNIT 13-05
Which one do you want? (apple)
WHICH ONES
IMG UNIT 13-06
Which ones do you want? (apples)
THIS / THAT ONE
IMG UNIT 13-07
This one is blue and that one is red. (teddy bear)
THESE / THOSE ONES
IMG UNIT 13-08
These ones are blue and those ones are red. (teddy bears)
THE ONE
IMG UNIT 13-09
The one on the left is more expensive. (dress)
THE ONES
IMG UNIT 13-10
The ones on the right are more expensive. (shoes)
THE + ADJECTIVE + ONE
IMG UNIT 13-11
The big one is a Dane and the small one is a Puli. (dog)
THE + ADJECTIVE + ONES
IMG UNIT 13-12
Which gloves do you like best, the white ones or the red ones?
A/AN + ADJECTIVE + ONE
IMG UNIT 13-13
His car is very old. He needs a new one.
SOME + ADJECTIVE + ONES
IMG UNIT 13-14
If you want tomatoes, I have some very good ones.

Remember!

The pronoun one is used to replace a singular countable noun. However, we use the pronoun ones when we replace plural countable nouns.
Singular Plural
Which one? Which ones?
This / that one These / those ones
The one The ones
The + adjective + one The + adjective + ones
A/an + adjective + one Some + adjective + ones