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 study of the subordinate conjunction. It must serve the purpose of some single part of speech. All other clauses are principal clauses.
+84. Classification of Subordinate Clauses.+—A. Subordinate clauses may be classified into substantive and modifying clauses.
Substantive clauses show the various substantive constructions. Thus:—