24 / PART ONE: THE BASICS Each main clause is separated from the next by a comma; ‘and’ precedes the last clause. ‘Or’ can also be used between two clauses. For your birthday, you may have a party or you can visit Alton Towers. Commas may be used to separate main clauses provided the last clause is preceded by ‘and’. The house, which had once been beautiful, was now a ruin. ‘Which’ is a relative pronoun, because it and the dependent clause both follow the subject of the sentence (the house). It is placed in the middle of the main clause and commas are used to separate it. The main clause is: ‘The house . . . . . . . . . . . . . . was now a ruin’. The dependent cause is ‘. . . . . . . . . had once been beautiful . . . . . .’. Other relative pronouns are: who, whose, whom, which, that. ‘That’ can be either a conjunction or a relative pronoun. It depends on how it is used. Joining clauses with relative pronouns Relative pronouns have a similar function to conjunctions. They link dependent clauses to main clauses and usually follow a noun. They are the same words as the interrogative pronouns: