All, both, half

All and half can be used with both countable and uncountable nouns:

All my friends were happy to hear the news; You’ve had all the fun; Half of the plums are bad; He spoke for about half an hour.

Both occurs only with countables in the plural:

Both his younger brothers are in the army.

All, both and half have ‘of’-constructions which are optional with nouns and obligatory with personal pronouns:

ALL my friends = ALL of my friends. But: ALL of them;

HALF his salary = HALF of his salary. But: HALF of it;

BOTH (the) students = BOTH of the students. But: BOTH of them.

All and both can also occur immediately after a noun or pronoun functioning as subject and after a pronoun functioning as object:

The students all like their new professor/They all like their new professor; The students both passed their exams; We both want to go; Take it all; Take them both.

When the predicate is compound or the verb form is analytical all and both can be placed within the predicate group:

The students were all working hard; They were all working hard; You must both work harder; They were all broken.

Half may be used in two different positions. It occurs both before the article and after it: half an hour/a half hour. However the pre-article position is much more common than its postposition to the article.

SUCH

Such means ‘of the same kind or degree as’ it occurs before the indefinite article with singular countable nouns, and without the article with plural countable nouns and uncountable nouns:

There was just such a case last year; All such possibilities must be considered; We had such awful weather.

Note:

In addition to the predeterminers mentioned above many may be used as predeterminer in the construction ‘many Art_ind N’: e.g. I’ve been here many a time.

2.43 Postdeterminers

Postdeterminers are words which follow determiners but precede adjectives in noun phrases. They fall into two groups: the indefinite pronouns many, several, (a) few, (a) little and numerals (cardinals and ordinals).

2.44 Indefinite pronouns used as postdeterminers

Many, several, few and a few co-occur with countable nouns in the plural while little and a little combine only with uncountable nouns:

His many old friends came to support him; We are all busy at our several tasks; A few Icelandic poppies were blooming; It has caused me not a little anxiety.

MANY

Many is mainly used in interrogative and negative sentences:

I haven’t made many mistakes; Were there many students at the meeting?

In informal English many is usually replaced by a lot of, lots of, plenty of, etc, when the sentence is affirmative:

There were such a lot of people in the shops.

However, when modified by too, so, a great many is quite common in affirmative constructions:

I’ve got a great many things to do today.

Many is seldom preceded by determiners.

Several

When several means ‘three or more’ it is seldom preceded by a determiner:

I’ve read it several times.

When it has the meaning ‘separate’, ‘individual’, it is normally preceded by a possessive pronoun:

They went their several ways.