Clauses of similarity, comparison, proportion, preference. Comment Clauses. Clauses of contrast and exception

Clauses of similarity are introduced by conjunctions (exactly) as, (just) as

Please do it (exactly) as I said/ instructed. (in the way that...)

If an as-clause is placed initially, the correlative form so, in formal literary English, may introduce the main clause.

(Just) as a moth is attracted by the light, (so) he was fascinated by her.

He looks as if he is going to be ill. He treated me as if he had never met me.

Clauses of comparison compare two ideas, one expressed by the principal clause and one by the comparative clause. They are compared with respect to something they have in common.

He is as quick in answering as his sister (is). He answers as quickly as his sister (does). He is not as/so quick in answering as his sister (is). His sister is quicker than he (is).

He moves more slowly than his sister (does).

Clauses of proportion express a proportionality/equivalence of tendency/degree between two circumstances. These clauses use conjunctions: the  ... the,  as ... (so)

The more she thought about it, the less she liked it. The harder he worked, the happier he felt. As he grew tired, (so) his work deteriorated.

Clauses of preference are introduced by conjunctions rather than, sooner than with a bare infinitive structure.

Rather than go there by air, I’ll take the slowest train.

 They’ll fight to the finish sooner than surrender.

 Rather than sitting quietly at home, he preferred to visit his friends.

 Rather than a new car, he bought a colour television.

Comment clauses represent a separate tone unit and perform the function of disjunct or (occasionally) conjunct. They often express the speaker’s attitude to the main clause or his manner of asserting it.

Food is cheap in England, I believe.

Kingston, as you probably know, is the capital of Jamaica.

I’m not sure what to do, to be honest.

I’m working the night shift, as you know.

Clauses of contrast use conjunctions whereas, while.

Mr Larson teaches physics, while Mr Corby teaches chemistry.

I ignore them, whereas my husband is always worried about what they think of us.

I like history, whereas my brother likes Math.

Clauses of exception use conjunctions except that, only, but that, save that, excepting that.

I would pay you now, except that I don’t have any money on me.

I would’ve asked you, only my mother told me not to.

Nothing would satisfy the child but that I place her on my lap.

Nothing would satisfy the child but for me to place her on my lap.

No memorial remains for the brave who fell on that battlefield, save that they will leave their image for ever in the hearts and minds of their grateful countrymen.