y 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:--

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