one fine day: ‘one’ specifies the number
this big tomato: ‘this’ specifies the big tomato that is nearby
some thick slices: ‘some’ specifies an indefinite amount.
1. the definite article (the) and the indefinite articles (a/an). These common expressions have complicated meanings. In general, the specifies a noun which is known to both speaker and hearer. The noun might be known, for example, because it is unique (the Eiffel tower), because it has been previously mentioned (the girl I told you about), or because it is fairly obvious that there is only one of the item in question (we went through the gate and knocked on the front door of the house). The can be used with singulars or plurals, countable or uncountable nouns.
The indefinite article is used when the speaker assumes that the noun is not previously known to the hearer or reader. The noun might be an unspecified member of a larger set of things (Would you like a banana?), or it might not matter which member of a larger set is referred to (Give him a round of applause!). Compare We went through the gate and knocked on the door to We went down a corridor and knocked on a door. A/an is only used with singular, countable nouns.
2. The demonstratives (this, that, these, those) specify the noun by indicating how close or far it is from speaker and hearer. This distance can be literal (Can you fetch that book over there?) or metaphorical (See these/those shoes – they’re killing me!). In the second example, the topic of the conversation, the shoes, is made more or less ‘immediate’ by varying the determiner.
3. In Scots, it is still possible to hear the relics of an old three-part system, this/that/thon/yon, where thon/yon can be used to specify nouns that are very far away. Alternatively, they can be used (e.g. See they shoes – they’re killing me!).
This/that are used with singular and uncountable nouns, while these/those are used with plural, countable nouns. Thon/yon/they can be used with singular or plural, countable or uncountable nouns.
4. The possessive adjectives (my, your, his/her/its, our, their) all specify the noun by indicating possession, e.g. my fat gerbil.
5. Enumerators (one, two, three, etc) specify countable nouns by expressing the exact quantity of them, e.g. two fried chickens.
6. Quantifiers (some, any, no, all, many, most, (a) few, fewer, more, less) specify nouns by expressing quantities that are less exact than enumerators. Some quantifiers have constraints on their uses, for example in questions some suggests that the speaker expects a positive answer, while any does not have such an expectation: compare Have you got some/any papayas today? Traditionally the comparative quantifier, less, was used with uncountable nouns (less money) and fewer was used with countable nouns (fewer people). However, especially in speech, less is being used with both countable and uncountable nouns (less people).
7. ‘zero determiner’: There is, of course, the option of not using a determiner at all to specify or categorise the noun, e.g.
Boys don’t cry.
Girls just wanna have fun.
However, the rules allowing the omission of the determiner vary across languages – in some languages there has to be a determiner in some contexts where it is optional in English. Moreover, the absence of a determiner in English also carries a meaning. In the above examples, we understand ‘boys’ and ‘girls’ to be general categories, not a specific group of boys or girls. For this reason, the absence of a determiner is sometimes redefined as the use of the ‘zero’ determiner in English; that is, the decision not to use a determiner is a grammatical option which itself carries meaning, and this option is realised differently in different languages.
8. Similar to determiners in some ways are partitive constructions. These have the structure ‘X of Y’, where Y is a set of items, expressed by a noun phrase, and X is a quantifier, or a comparative or a superlative adjective, e.g.
many of the children
the more boisterous of the children
the happiest of the children.
Partitive constructions, like determiners, identify part of a total set of items (compare ‘some children’ with ‘some of the children’).
