Adversative coordination. It is performed by the adversative conjunctions but, while, whereasand the conjunctions nevertheless (nonetheless — formal), still, yet.
§ Jane has dressed in brown while Mary was wearing blue.
(4)Causative-consecutive coordination. It is performed by the conjunctions for, so and the conjunctive adverbs therefore,accordingly, consequent1y, hence.
§ She found a job in London, for she wanted to go there with her baby boy.
§ I’ve brought the wrong key, so I can’t open the door.
Coordinate clauses can also be connected asyndetically, separated by a comma, a semicolon or a colon, the relations between clauses coordinated asyndetically are similar to those connected by conjunctions.
§ The moon went down, the stars grew pale, the cold day broke.
§ Some people work best in the mornings; others do better in the evening.
§ We have had to abandon our holiday plans: the dates didn’t work out.
A complex sentence has two or more clauses, at least one of which is subordinated to another. The independent clause which is identical with the sentence as a whole is called a main (principal) clause, while the dependent clause is called a subordinate clause.
§ No one knowswhat caused the accident.
However, there is no main clause in a complex sentence when either its subject (1) or predicative (2) is expressed by a clause.
1) What caused the accident is a complete mystery.
2) The question is what caused the accident.
The clauses of a complex sentence may be connected asyndetically, or by means of a subordinator: a subordinating conjunction or conjunctive word (pronoun or adverb).
§ I wish you knew that.
§ I knew that he was right.
§ He always knew what was the right thing.
There is some difference between a conjunction and a conjunctive word. A conjunction is only a structural element connecting two clauses it does not have ‘any other’ function in the sentence. A conjunctive word does not only serve as a connector, but it also has a syntactic function of its own in the subordinate clause it introduces. Compare:
§ I knew that something had happened (conjunction).
§ No one was consulted on who should have the prize (conjunctive pronoun).
A subordinate clause may follow, precede or interrupt the main clause.
§ I had it before she came.
§ As I was in a hurry, I had to take a taxi.
§ The letter which she wrote was never posted.
A subordinate clause may itself subordinate one or more other clauses, so that hierarchy of clauses, one within another, may be built up. In such cases we distinguish clauses of the 1st, 2nd, 3rd degree of subordination. The subordination of the kind is called consecutive.
I think you can doit if you try.
A main clause of a complex sentence forms a unit resembling a simple sentence in which some part is replaced by a clause. In other words, the functions of subordinate clauses are similar to those of the parts of a simple sentence. By function, i.e. the part they play in the main clauses, subordinate clauses are classified as subject (1), predicative (2), object(3), attributive(4) and adverbial(5) clauses.
§ What you need is plenty of exercise.
§ This is where we disagree.
§ Do you know who is coming?
§ We saw her friend, who works in a shop.
§ He shook his head again when Gertrude offered him money.
Subordinate clauses may be connected by means of a coordinating conjunction with some part of the sentence as homogeneous members, which also shows that their functions are similar to those of the parts of a simple sentence.
§ I thought of the fifty guineas, and of how very useful they would be to me.
Two or more subordinate clauses may be homogeneous. Like homogeneous sentence parts, homogeneous clauses are connected by coordinating conjunctions or asyndetically.
§ Her bright calm face lighted up with pleasure as we went to meet him, and as they came in, hand in hand.
§ She had expected that it would be more difficult, that something cold and hard would be said.