The commonest place where indirect subordination occurs is in RELATIVE CLAUSES. Relative clauses function as modifiers within phrases in the same way as AjP's and PP's. Semantically, they fulfil the adjectival function of adding information to NP's.
Thus, the information conveyed by the three examples below is approximately the same in all cases:
The modifiers in all three examples modify the noun boy and are therefore placed within the NP brackets. The fully analysed version of (14c) is:
Note that the elements within the RCl are also fully analysed.
Relative clauses are (relatively) easy to recognise. They are introduced by RELATIVE PRONOUNS, which function as elements in the clause (S,O). These include: who, whom, whose, which, that. In (14d) the relative pronoun is the subject. This shows that SCl's must be analysed according to their own internal structure.
If a relative pronoun is the subject of the relative clause, then it must be included in the sentence. If it is the object, it is often omitted in colloquial language. Compare:
Relative clauses can also be introduced by relative adverbs, such as where, when, why, how. Relative adverbs and relative pronouns are together sometimes described as "wh-elements".
Compare:
In 17b there is a "stranded" preposition. (Compare the similar problems with verbs discussed in 7.4.)
Note that relative adverbs should not be confused with the conjunctions introducing adverbial clauses. (See Unit 8)
In NCl's that is a conjunction. In RCl's it is a pronoun and has a SPOCA function. In RCl's, but not NCl's, you can substitute who or which for that.
Relative clauses sometimes act as a comment on a clause or sentence, in much the same way as attitude adverbs. In such cases they function as adverbials.