Substantive clauses show the various substantive constructions.  Thus:—­

1.  Subject:  ["Thou shalt not covet,” is the tenth commandment].

2.  Object:  [I know what you wish].

3.  Appositive:  [The truth that the earth is spherical is generally believed].

4.  Attribute complement:  [The truth is that she is not well].

Modifying clauses show adjective and adverbial constructions.

Thus:—­

1.  Adjective:  [The house which you see is mine].

2.  Adverb:  [I will go when it is possible].

B. Subordinate clauses may also be classified according to the introductory word.

(a) Clauses introduced by relative or interrogative pronouns:  who, which, what, that (= who or which), as (after such), and the compound relatives, whoever, whichever, whatever (the first three are both relative and interrogative):  [The school that stands on the hillside is painted white.  I know whom you mean].

(b) Clauses introduced by a relative or interrogative adjective:  [The man whose library is well furnished is rich.  I see which way I ought to take].

(c) Clauses introduced by a relative or interrogative adverb, such as when, whenever, since (referring to time), until, before, after, where, whence, whither, wherever, why, as, how:  [I know the house where lie lives].

(d) Clauses introduced by a subordinate conjunction, such as because, since (= because), though, although, if, unless, that (= in order that), as, as if, as though, then:  [I will go since you wish it].

C. Subordinate clauses may also be classified according to the nature of the thought expressed.

(a) General description:  [The house, which stands on the hill, has a fine view].

(b) Place:  [The house where he was born is torn down].

(c) Time:  [He works whenever he can].

(d) Cause:  [Since you wish it, I will go].

(e) Concession:  [Although he is my friend, I can see his faults].

(f) Purpose:  [Run, that you may obtain the prize].

(g) Result:  [She was so tired that she stumbled].

(h) Condition:  [If it rains, we shall not go].

(i) Comparison:  [You look as if you were tired].

Note that the subordinate clauses in the above examples are modifying clauses.

(j) Direct quotation:  [She said, “I will go"].

(k) Indirect statement:  [She said that she would go].

(l) Indirect question:  [I knew where his house was].

Note that the subordinate clauses in the above examples are substantive clauses.