to play Indian, _but_ Richard
preferred to play railroad].

The cooerdinating conjunction need not actually appear in the sentence. Its
omission is then indicated by the punctuation: [John wished to play
Indian; Richard preferred another game].

+81. Subordinate Conjunctions and Complex Sentences.+--A _subordinate_
conjunction is used to join a subordinate clause to a principal clause,
thus forming a _complex_ sentence. The test to be applied to a clause in
order to ascertain whether it is a subordinate clause, is this: if any
group of words in a sentence, containing a subject and predicate, fulfills
the office of some single part of speech, it is a _subordinate_ clause. In
the sentence, "I went because I knew that I must," the clause, "because I
knew that I must" states the reason for the action named in the main
clause. It, therefore, stands in _adverbial_ relation to the verb "went."
"That I must" is the object of "knew." It, therefore, stands in a
_substantive_ relation to the verb.

Subordinate clauses are often introduced by subordinate conjunctions
(sometimes by relative pronouns or adverbs); but, whenever such a
clause appears in a sentence, otherwise simple, the sentence is _complex_.
If it appears in a sentence otherwise compound, the sentence is
_compound-complex_.

The different types of subordinate clauses will be discussed later.

SENTENCE STRUCTURE

+82. Phrases.+--Phrases are classified both as to structure and use.

From the standpoint of structure, a phrase is classified from its
introductory word or words, as:--

1. _Prepositional_: [They were _in the temple_].

2. _Infinitive_: [He tried _to make us hear_].

3. _Participial_: [_Having finished my letter_].

Classified as to use, a phrase may be--

1. A _noun_: [_To be good is to be truly great_].

2. An _adjective_: [The horse is an animal _of much intelligence_].

3. An _adverb_: [He lives _in the city_].

+83. Clauses.+--It has been already shown that clauses may be either
principal or subordinate. A principal clause is sometimes defined as "one
that can stand alone," and is therefore independent of the rest of the
sentence. This statement is misleading, for, although true in most cases,
it does not hold in cases like the following:--

1. As the tree falls, so it must lie.

2. That sunshine is cheering, cannot be denied.

The genuine test for the subordinate clause is the one already given in
connection with the stud