We use as…as with an adjective or adverb in between to say that something or someone is like something or someone else, or that one situation is like another:
- - Was the film as funny as his last one?
- - Andrew came round to my flat as quickly as he could.
Negative forms of sentences like this can use either not as or not so. In formal speech and writing it is more common to use less than:
- - The gap between the sides is not as wide as it was. (or … is less wide than it was.)
- - The bees are plentiful, but not so common as last summer. (or …but less common than last summer.)
- - Some people find cooking easy, but others are not as/so fortunate (as these).
We use not so rather than not as in a number of common expressions. For example: I´m not so sure; It´s (= the situation is) not so bad; Not so loud! (= be more quiet); He´s not so good (=not very well).
If you put a countable noun between the adjective and the second as, you should use a/an in front of the noun (if the noun is singular):
- - Despite his disability, he tried to lead as normal a life as possible.
- - She was as patient a teacher as anyone could have had.
The negative form of sentences like this can use either not as or sometimes not such:
- - He´s not as good a player as he used to be.
- - He´s not such a good player as he used to be. (Notice the different word order.)
- - They´re not such terrible children as we´d expected. (We don´t use not as with plural nouns.)
We can use how, so and too followed by an adjective in a similar way:
- - How significant a role did he play in your life?
- - It´s not quite so straightforward a problem as it might at first seem.
- - Conspiracy is perhaps too strong a word.
- - How big a piece do you want?
As…as is also used in sentences with much and many to talk about quantities:
- - She earns in the English school at least as much as Mark, and probably more.
- - Dublin has twice as many banks as the rest of south-east Ireland.
We also use as much/many as or as little/few as to say that a quantity or amount is larger or smaller than expected. Many and few are used before numbers; much and little are used with amounts such as $5 and 20%, and distances such as 3 metres:
- - There is a small number involved, possibly as few as a hundred. (not…as little as…)
- - Prices have increased by as much as 300 per cent.
We can use so followed by an adjective or an adverb and a that-clause in sentences such as:
- - The recipe was so simple that even I could cook it. ( =because the recipe was so simple, even I could cook it).
- - He was walking so slowly that before too long we caught him up. ( = because he was walking so slowly…)
Less commonly we use so followed by an adjective and as to with a similar meaning:
- - The difference was so small as to not be worth arguing about. ( = because the difference was so small, it wasn´t worth arguing about).