Positive adjectives and adverbs can be used for comparing. Several different grammatical structures are possible.
As … as …
This structure is used to say that people, things, actions or events are equal in a particular way.
- A car is as fast as a bus.
- Alice is as beautiful as Mary.
- Tom is as tall as Harry.
If we want to say that people, things etc are unequal in a particular way, we can use not so … as … or not as … as …
- Tom is not as/so tall as Harry.
- A car is not as/so fast as a train.
- Alice is not as/so beautiful as Susie.
No other as … as …
This structure can be used to compare one person or thing with the whole group that she/he/it belongs to.
- No other girl is as intelligent as Alice.
- No other metal is as useful as iron.
- No other river is as long as the Niles.
As much/many … as …/as few/little … as…
This structure is used to make a comparison of quantity.
- I earn as much money as you.
- Alice has as many children as Mary.
- Tom earns as much as Harry.
- We have as many cars as them.
- They have as few visitors as we have.
- They have as little money as we have.
In an informal style, we use object pronouns (us, them, him etc.) after as. In a more formal style, subject pronouns are used usually with verbs.
- I earn as much money as he does.
- We have as many children as they have.
Not as much/many … as …
This structure can be used to say that quantities are not equal in a particular way.
- He does not earn as much as I do.
- Harry does not eat as much food as Tom does.
- We do not have as many visitors as them