22.    than/as + pronoun + auxiliary

A.    When the same verb is required before and after than/as we can use an auxiliary for the second verb

I earn less than he does  (less than he earns) The same tense need not be used in both clauses

He knows more than I did at his age

B.     When the second clause consists only of than/as + I/we/you + verb, and there is no change of tense, it is usually possible to omit the verb

I'm not as old as you (are)        He has more time than I/we (have) In formal English we keep I/we, as the pronoun is still considered to be the subject of the verb even though the verb has been omitted In informal English, however, me/us is more usual

He has more time than me        They are richer than us

C.     When than/as is followed by he/she/it + verb, we normally keep the verb   You are stronger than he is

But we can drop the verb and use he/she/they in very formal English or him/her/them in very colloquial English.

These rules apply also to comparisons made with adverbs

I swim better than he does /better than him

They work harder than we do /harder than us

You can't type as fast as I can /as fast as me