Substitute one/ones
An object that has already been mentioned or is visible in the discourse can be referred to by the head-word one, plural ones. These words have no semantic identity of their own, but only the grammatical function of substituting for a noun or NG in order to avoid repetition. When used in this way, these items are classed as ‘substitute heads’, to distinguish them from the classes of ‘pronominal heads’ of NGs.
It is important to note that one/ones can replace either a whole antecedent NG or only part of it. Compare 1 and 2 with 3. In 4, the elliptical plural some, not ones is the plural of one:
1 I knew Mavis wanted a blue scarf, so I bought her one. (one = whole NG a blue scarf)
2 I knew Mavis wanted a blue scarf, so I bought her a lovely one. (= blue scarf ).
3 I couldn’t find a blue scarf for Mavis, so I bought her a green one. (= scarf )
4 I know Mavis likes scarves, so I bought her some lovely ones. (= scarves)
The substitute item one/ones may be accompanied by a determiner, a pre-modifier or a post-modifier, thus producing NGs of varying structures:
dh: this one, each one, either one, which ones, any ones
dmh: the only one, that big one, a small red one, a few ripe ones
dhm: that one over there, any one you like
dmhm: some fresh ones from the country
Possessive determinatives are rarely used before one/ones in standard English. In informal language – but not in best usage – some speakers might say my one, Peter’s one, my friend’s ones, those ones.
