Collins Cobuild English Grammar (193 page)

one eight seven two

eighteen seventy-two

Note that you cannot use
a
instead of
one
for the second way.

The third way is often used to identify something such as a room number. With telephone numbers, you always say each figure separately like this.

The last way is used if the number is a date.

R45
    Unlike some other languages, in English when numbers over 9999 are written in figures, a comma is usually put after the fourth figure from the end, the seventh figure from the end, and so on, dividing the figures into groups of three. For example, 15,500 or 1,982,000. With numbers between 1000 and 9999, a comma is sometimes put after the first figure. For example 1,526.

When a number contains a full stop, the number or numbers after the full stop indicate a fraction. For example,
2.5
is the same as two and a half.

Ordinal numbers

R46
    Here is a list of ordinal numbers. The list shows the patterns of forming ordinal numbers greater than 20.

R47
    As shown in the above list, ordinals can be written in abbreviated form, for example in dates or headings, or in informal writing. You write the last two letters of the ordinal after the number expressed in figures. For example,
first
can be written as
1st
,
twenty-second
as
22nd
,
hundred and third
as
103rd
, and
fourteenth
as
14th
.

…on August
2nd
.
…the
1st
Division of the Sovereign’s Escort.

Fractions and percentages

R48
    You can write a fraction in figures, for example
¹
/
₂
,
¹
/
₄
,
³
/
₄
, and
²
/
₃
. These correspond to
a half
,
a quarter
,
three-quarters
, and
two-thirds
respectively.

R49
    Fractions are often given in a special form as a number of hundredths. This type of fraction is called a
percentage
. For example,
three-hundredths
, expressed as a percentage, is
three per cent
. It can also be written as
three percent
or
3%
.
A half
can be expressed as
fifty per cent
,
fifty percent
, or
50%
.

About
60 per cent
of our students are women.
Ninety percent
of most food is water.

Before 1960
45%
of British trade was with the Commonwealth.

You can use percentages on their own as noun phrases when it is clear what they refer to.

Ninety per cent
were self employed.
…interest at
10%
per annum.

Verb forms and the formation of verb phrases

R50
    Verbs have several forms. These forms can be used on their own or combined with special verbs called
auxiliaries
. When a verb or a combination of a verb and an auxiliary is used in a clause, it is called a
verb phrase
. Verb phrases can be
finite
or
non-finite
. If a verb phrase is finite, it has a
tense
. A
non-finite
verb phrase contains a verb in the form of an
infinitive
or an
-ed
or
-ing
participle
.

Verb phrases are used to refer to actions, states, and processes. The use of verb phrases in clauses to make statements is explained in
Chapter 3
.

R51
    Verb phrases can be
active
or
passive
. You use an active verb phrase if you are concentrating on the performer of an action, and you use a passive verb phrase if you are concentrating on someone or something that is affected by an action. Further information on the use of passive verb phrases is given in
Chapter 9
(
9.8
to
9.24
).

R52
    Regular verbs have the following forms:

a base form e.g.
walk

an
s
form e.g.
walks

an
-ing
participle e.g.
walking

a past form e.g.
walked