I gave him the textbook in order he might learn his lesson.

The conjunctions lest and for fear that introduce clauses stating what is to be prevented, as both the conjunctions have a negative meaning. Lest is extremely formal and after it the Subjunctive mood usually with should is used.

We wrapped the instruments in oilcloth lest they should be damaged by sea water.

Take an electric torch for fear you get off the path.

Adverbial clauses of condition state the condition (either real or unreal) which is necessary for the realization of the action expressed in the principal clause. They are introduced by the conjunctions it, unless, in case, suppose, on condition that, provided, etc.

If I see him tomorrow, I shall ask him about it.

He won't go there unless he is invited.

We can deliver the machine in December provided (that) we receive your order within the next ten days.

Conditional clauses may be joined to the principal clause asyndetically by means of link-inversion. Inversion is possible only if the predicate is in the Subjunctive mood.

Had she been an English woman, she would have never behaved like that.

Depending on the relation between the subordinate and the principal clauses and on the use of tense and mood forms, conditional clauses may be subdivided into three types:

1. Clauses of real condition, when the actions or events in both the clauses refer to the past or present and these actions or events are regarded as real facts. If the actions or events refer to the future, they are regarded as real possible facts.

If the weather is fine tomorrow, we shall go to the country.

If he is here, he is probably working in the library.

If he called on them yesterday, they gave him your letter.

2. Clauses of possible condition. These clauses denote hypothetical situations or circumstances which may be or may not be realized in the present or future. Accordingly the Subjunctive mood forms are used both in the subordinate and the principal clause to denote actions or states.

If I saw my friend tomorrow, I should ask him about it.

You wouldn't be talking that way unless you were hurt.

In case the state of the patient become worse, he would be taken to hospital.

Should he ask for reference, tell him to apply to me.

3. Clauses of unreal condition imply non-fulfilment of the condition, as the actions or events described in the conditional clause refer to the past and the time of their realization is over.

If the book had been published, they could have bought a copy in the shops.

He wouldn't have caught cold if he had put on warm coat.

She would have been playing her part well unless she had been stiff with fright.

A complex sentence with a conditional clause may be built on clauses of type II and III, this forming a mixed type of conditional relationship.

If you had worked harder last year, you would know English well now.

If he knew English well, he would have translated the article without difficulty yesterday.

Adverbial clauses of concession denote the presence of some obstacle which nevertheless does not hinder the action expressed in the principal clause. They are introduced by the following conjunctions and connectives: though, although, no matter how, however, whatever, whichever, even if, even though, even when, for all that, despite that, in spite of the fact etc.

Though it was only nine o'clock, there were few people in the streets.

He went out in spite of the fact that he had a bad cold.

The conjunction as introduces adverbial clauses of concession in which the predicative stands first.

Troubled as he was, he never exposed his difficulties to her.

Dark as it was getting, I could still see these changes.

Adverbial clauses of result denote some consequence or result of the action expressed in the principal clause. Very often adverbial clauses of result have an additional meaning of degree. Adverbial clauses of pure result are introduced by the conjunction so that.

He went to the lecture early so that he got a good seat.

She sat behind me so that (so) I could not see the expression on her face.

Adverbial clauses of result with an additional meaning of degree are introduced by the conjunction that; in this case we find the adverbs so or pronoun such in the principal clause.

He is so weak physically that he can hardly move.

I was in such astonishment that I could hardly speak.

Adverbial clauses of manner characterize in a general way the action expressed in the principal clause. They are introduced by the conjunctions as, as it, as though, the way. In adverbial clauses of manner the idea of comparison is often implied.

She cooks the turkey exactly as my mother did.

You answered as if you did not know the rule.

I'm sorry I talked the way I did at lunch.

There are different types of adverbial clauses of manner.

1. Clauses of manner of the first type modify the predicate of the principal clause by attributing some quality to it.

He could do it as no one else could have done.

You ought to write as he does.

2. Clauses of manner of the second type refer to attributes or predicatives characterizing a state or quality of a person.

Astonished, as one could be in such circumstances, he didn't give a sign of it.

He was puzzled by the situation, as one could easily be in his place.

3. Clauses of manner of the third type refer to an adverbial modifier giving additional information or explanation concerning it.

He said it with contempt, as a serious man should treat such views.

Adverbial clauses of comparison denote an action with which the action of the principal clause is compared. They are introduced by the conjunctions than, as… as, not so… as, as it, as though, like.

He was weak and pale as if he had not slept for many nights.

They don't have long intervals like they do at other theatres.

We were going up the road as fast as we could.