English Relative Clauses - Overview

Overview

The basic grammatical rules for the formation of relative clauses in English are given here. More details can be found in the sections below, and in the article on who.

1. The basic relative pronouns are who, which and that (but see Status of that below).
2. The relative pronoun comes at the very start of the relative clause, unless it is preceded by a fronted preposition: "The bed on which I was lying" (in informal English it is more normal to leave the preposition "stranded": "The bed which I was lying on"). More rarely the relative clause may start with a larger phrase containing the relative pronoun after a preposition: "The bed, the owner of which we had seen previously, ...", "The bed, lying on which was a small cat, ..."
3. who can be used only with an antecedent referring to a person; which, referring to a thing; that, referring to either person or thing. ("The man who ..."; "The thing which ..."; "The man/thing that ...".)
4. that can be used only in restrictive relative clauses, while who and which can be used in both restrictive and non-restrictive clauses. ("The man that/who ..."; "The thing that/which ..."; "My friend, who ..."; "My car, which ...".) In some styles of formal English, particularly American, use of which in restrictive clauses is avoided where possible (see that or which below).
5. whom is a variant of who normally used only in formal English, and only when the antecedent's role in the relative clause is as an object — not a subject. ("The man who saw me"; "The man who/whom I saw".)
6. However, when a preposition in the relative clause is fronted, only whom (rarely who) and which can be used. ("The man who/whom/that I spoke to"; formal "The man to whom I spoke" — rarely *to who, not *to that; "The knife which/that I killed him with"; formal "The knife with which I killed him" — not *with that.)
7. In the positions where that can be used as relative pronoun (namely in restrictive relative clauses without a fronted preposition), provided it is not the subject of the relative clause, it is also possible to omit the relative pronoun entirely. For example: "The man who(m)/that I saw" or "The man who(m)/that I spoke to" can also be rendered as simply "The man I saw" or "The man I spoke to". However such omission is not possible in "My friend, who I saw" (non-restrictive relative clause), "The man to whom I spoke" (fronted preposition), or "The man who/that saw me" (relative pronoun is the subject).
8. The relative pronoun takes the number (singular or plural) and person (first, second, or third) of its antecedent: "The people who were present" (who takes the plural verb were because its antecedent is the plural people); "I, who am normally very tolerant, ..." (who takes the first-person singular verb am because its antecedent, the pronoun I, is first-person singular).
9. whose indicates that the antecedent has a possessive role in the relative clause. ("The man whose daughter I married".) Unlike who, it can be used with antecedents referring to either persons or things ("I found a car whose battery was dead"), although its use referring to things is relatively uncommon in informal English (more natural might be, for example, "I found a car with a dead battery"). It can be used in both restrictive and non-restrictive clauses ("John, whose brother was recently married, ...") and with both fronted and stranded prepositions ("The man in whose car we arrived ...", "The man whose car we arrived in ...").
10. Relative clauses whose antecedent is a whole proposition are formed with which: "The cake was burnt, which made me angry" (here which refers to the circumstance of the cake's being burnt).
11. A less common, usually quite formal, use of which is as a relative determiner (adjective), as in "He painted a picture of the house, which painting I later destroyed." Here it can be used with nouns referring to either persons or things.
12. Free relative clauses (which have no antecedent, but themselves take the role of an argument in the main clause) can be formed with who(m) or who(m)ever (referring to people), what or whatever (referring to things), whichever (referring to people or things from a known set). These can be called compound relative pronouns. For example, "I'll take who(m)(ever) you choose" (where the pronoun stands for "the person(s) who(m)"); "What I said annoyed her" (where the pronoun what stands for "the thing which" or "that which"). There are also determiner (adjectival) equivalents: which/what or more usually whichever/whatever: "I'll take whichever dish you choose."

Notice that all the words used as relative pronouns also have other uses in English grammar: that can be a demonstrative or a conjunction, while which, what, who, whom and whose can be interrogative words. For other uses of whoever etc., see -ever.