+441.+ The simple sentence is the unit of speech. It is a combination of
words which makes a single statement, question or command. But many
times a constant repetition of these short sentences would become
tiresome, and our written and spoken speech would not flow as smoothly
and rapidly as we desire. So we have evolved a way in which we may
combine these sentences into longer statements. Let us take the two
_simple_ sentences:
We are united.
We shall succeed.
We may combine these into a single sentence by using the co-ordinate
conjunction _and_. Then our sentence reads:
We are united and we shall succeed.
This is a _compound_ sentence, formed by uniting two simple sentences.
Both of the clauses are independent and are of equal rank. Neither
depends upon the other. They are united by the co-ordinate conjunction
_and_. We can combine these sentences in a different way. For example,
we may say:
If we are united, we shall succeed.
Now we have a subordinate clause, _if we are united_, which is used to
modify the verb of the main clause, _succeed_. We have used the
subordinate conjunction _if_, and so we have a _complex_ sentence formed
by uniting the principal clause and a dependent clause.
+442.+ The next step in sentence building, after the simple sentence, is
the complex sentence. A complex sentence is a combination of two or more
simple sentences, which are so united that one sentence remains the main
sentence--the backbone, as it were--and the other sentence becomes
subordinate or dependent upon it.
+443.+ +A complex sentence is one containing a principal clause and one
or more subordinate clauses.+
+A principal clause is one which makes a complete statement without the
help of any other clause or clauses.+
+A subordinate or dependent clause is one which makes a statement
dependent upon or modifying some word or words in the principal clause.+