Relative Clauses (4) - Prepositions In Relative Clauses

In formal styles, we often put a preposition before the relative pronouns which and whom:
Example: The rate (at which) a material heats up depends on its chemical composition.
Example: In the novel by Peters, (on which) the film is based, the main character is a teenager.
Example: An actor (with whom) Gels on had previously worked contacted him about the role.
Example: Her many friends, (among whom) I like to be considered, gave her encouragement.

Notice that after a preposition you can't use 'who' instead of 'whom', and you can't use 'that' or 'zero relative pronoun':
Example: Is it right that politicians should make important decisions without consulting the public to (whom) they are accountable? (not... the public to who they are accountable.)
Example: The valley (in which) the town lies is heavily polluted (not The valley in that the town... )

In informal English, we usually put the preposition later in the relative clause rather than at the beginning:
Example: The office (which) Graham led the way to was filled with books.
Example: Jim's footballing ability,(which) he was noted (for), had been encouraged by his parents.
Example: The playground wasn't used by those children (who) it was built (for).

In this case, we prefer 'who' rather than 'whom'. In defining relative clauses,we can also use 'that' or 'zero relative pronoun' instead of 'who' or 'which' (e.g... the children (that) it was built for).

If the verb in the relative clause is a two or three - word verb (e.g. come cross, fill in, go through, look after,look up to, put up with, take on), we don't usually put the preposition before the relative pronoun:
Example: Your essay is one of those (which/ that) I'll go (through) tomorrow. (rather than... through which I'll go tomorrow.)
Example: She is one of the few people (who/ that) I look up (to). (not... to whom I look up.)

In formal written English, we often prefer to use 'of which' rather than 'whose' to talk about things:
Example: A huge amount of oil was spilled, the effects (of which) are still being felt. (or... whose effects are still being felt.)
Example: The end of the war, the anniversary (of which) is on the 16th of November, will be commemorated in cities throughout the country (or... whose anniversary is on...)

Notice that we can't use 'of which' instead of 'whose' in a non - defining relative clause:
Example: Dorothy was able to switch between German,Polish and Russian, (all of which) she spoke fluently (not... all whose she spoke...)

We can sometimes use 'that... of' instead of 'of which'. This is less formal than 'of which' and 'whose' and is mainly used in spoken English:
Example: The school (that) she is head (of) is closing down (or The school of which she is head... )

'Whose' can come after a preposition in a relative clause.However, it is more natural to put the preposition at the end of the clause in less formal contexts and in spoken English:
Example: We were grateful to Mr Marks, (in whose) car we had travelled home. (or... whose car we had travelled home in.)
Example: I now turn to Freud, (from whose) work the following quotation is taken.(or... whose work the following quotation is taken from.)

In this article, learners of English can study not only relative clauses but also prepositions. Then, students can learn the usage of prepositions in relative clauses.

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