Blog about English
Using prepositions before or after relative pronouns.
A preposition required by the verb or expression in a relative clause can appear either before the relative pronoun or at the end of the clause.
For example, The person to whom I spoke and The person who I spoke to express the same basic relationship.
In everyday and neutral English, the preposition commonly appears at the end of a relative clause.
For example, The person who I spoke to was helpful.
In formal English, the preposition can be placed directly before the relative pronoun.
For example, The person to whom I spoke was helpful.
When a preposition directly precedes a relative pronoun referring to a person, whom is normally used rather than who in formal English.
For example, The person to whom I spoke was helpful.
A preposition can directly precede which when the relative pronoun refers to a thing or animal.
For example, The system on which the software runs is secure.
That is not normally used directly after a preposition in a relative clause.
Use which or whom in formal constructions, or move the preposition to the end: The book about which we spoke and The book that we spoke about.
Who is not normally used directly after a preposition in formal relative-clause constructions.
Use whom instead: The person to whom I spoke. In ordinary English, The person who I spoke to is much more common.
The preposition in a relative clause is determined by the verb, adjective, noun, or expression that requires it.
For example, the person I spoke to, the company I work for, and the subject we were talking about.
Phrasal and prepositional verbs retain their required particle or preposition when used in relative clauses.
For example, the person I was talking to, the problem we need to deal with, and the subject she brought up.
Preposition placement often distinguishes formal style from everyday conversational style.
For example, The person to whom I spoke is formal, while The person I spoke to is natural in ordinary conversation.
Both end-position and fronted prepositions can occur in defining relative clauses.
For example, The company for which I work and The company I work for are both standard.
Prepositions can appear in either position in non-defining relative clauses, although fronted prepositions are especially associated with formal style.
For example, My colleague, with whom I work, is moving abroad and My colleague, who I work with, is moving abroad.
When the preposition remains at the end of a defining relative clause, an object relative pronoun can often be omitted.
For example, The person who I spoke to and The person I spoke to are both standard.
When a preposition directly precedes the relative pronoun, the pronoun cannot normally be omitted.
For example, The person to whom I spoke requires whom after the preposition.
Preposition + whom is especially common in formal, academic, legal, and professional writing.
For example, The individual with whom the company contracted signed the agreement.
Preposition + which is commonly used in formal writing when referring to things, systems, documents, and concepts.
For example, The procedure by which the data were collected was carefully documented.
Common verbs and expressions can retain their prepositions at the end of a relative clause or move them before which or whom.
For example, the project on which we worked and the project we worked on.
Preposition + which is common when the antecedent is an abstract noun referring to a method, reason, process, or circumstance.
For example, the method by which the problem was solved and the reason for which the decision was made.
Some prepositional relationships can instead be expressed using relative adverbs such as where, when, and why.
For example, the place in which I work can be expressed as the place where I work.
Where can often replace in which when the antecedent refers to a place.
For example, The office in which she works and The office where she works are both standard.
When can sometimes replace in which when the antecedent refers to a time or period.
For example, The year in which she graduated and The year when she graduated are both possible.
Why can sometimes replace for which when the antecedent refers to a reason.
For example, The reason for which he left is unclear and The reason why he left is unclear.
Prepositions can occur elsewhere in clauses containing whose, but whose itself already expresses a possessive relationship.
For example, The company whose products we talked about is expanding.
Do not add a preposition merely because the relative clause contains a relative pronoun; use only the preposition required by the underlying verb or expression.
For example, The person whom I met is correct, while The person with whom I met is incorrect unless the underlying meaning specifically requires with.
Use the correct preposition with the underlying verb or expression and place it appropriately for the intended register.
Common mistakes include using who after a fronted preposition, using that directly after a preposition, omitting the relative pronoun after a fronted preposition, adding an unnecessary preposition, and choosing the wrong preposition for the verb.