ABSTRACT
This chapter discusses a small group of words that are very important in English grammar. They are important because they serve three very different functions. These words are which, who, whom, whose, what, when, where, why and how. They are sometimes called 'wh- words' because they all start with those two letters. As question words - sometimes called 'interrogatives' - they introduce one type of interrogative sentence. As relative words - sometimes called 'relativisers' - they introduce relative clauses, which function as the postmodification of noun phrases. Two words in this group, what and how, do not function as relative words. As subordinators they introduce nominal or adverbial subordinate clauses. Adverbial subordinate clauses function as adverbials in the main clause. In this they are similar to subordinating conjunctions in general. These three functions cut across the traditional word class distinctions in terms of word class pronoun, determiner and adverb.
