Numerals are determiners when they appear before a noun. In this position, cardinal numerals express quantity:
one book two books twenty books
In the same position, ordinal numerals express sequence:
first impressions second chance third prize
The subclass of ordinals includes a set of words which are not directly related to numbers (as first is related to one, second is related to two, etc). These are called general ordinals, and they include last, latter, next, previous, and subsequent. These words also function as determiners:
next week last orders previous engagement subsequent developments
When they do not come before a noun, as we've already seen, numerals are a subclass of nouns. And like nouns, they can take determiners:
the two of us the first of many
They can even have numerals as determiners before them:
five twos are ten
In this example, twos is a plural noun and it has the determiner five before it.
Pronouns and Determiners
There is considerable overlap between the determiner class and the subclass of pronouns. Many words can be both:
Pronoun
Determiner
This is a very boring book
This book is very boring
That's an excellent film
That film is excellent
As this table shows, determiners always come before a noun, but pronouns are more independent than this. They function in much the same way as nouns, and they can be replaced by nouns in the sentences above:
This is a very boring book
~Ivanhoe is a very boring book
That's an excellent film
~Witness is an excellent film
On the other hand, when these words are determiners, they cannot be replaced by nouns:
This book is very boring
~*Ivanhoe book is very boring
That film is excellent
~*Witness film is excellent
The personal pronouns (I, you, he, etc) cannot be determiners. This is also true of the possessive pronouns (mine, yours, his/hers, ours, and theirs). However, these pronouns do have corresponding forms which are determiners:
Possessive Pronoun
Determiner
The white car is mine
My car is white
Yours is the blue coat
Your coat is blue
The car in the garage is his/hers
His/her car is in the garage
David's house is big, but ours is bigger
Our house is bigger than David's
Theirs is the house on the left
Their house is on the left
The definite and the indefinite articles can never be pronouns. They are always determiners.
The Ordering of Determiners
Determiners occur before nouns, and they indicate the kind of reference which the nouns have. Depending on their relative position before a noun, we distinguish three classes of determiners.
Predeterminer
Central Determiner
Postdeterminer
Noun
I met
all
my
many
friends
A sentence like this is somewhat unusual, because it is rare for all three determiner slots to be filled in the same sentence. Generally, only one or two slots are filled.
Predeterminers
Predeterminers specify quantity in the noun which follows them, and they are of three major types:
1. "Multiplying" expressions, including expressions ending in times:
twice my salary double my salary ten times my salary