Relative clauses with prepositions

Relative clauses are used to add information to a noun in a main clause. This usually happens to make two pieces of information, that would otherwise be contained in two separate main clauses, more concise. The noun in the second main clause is changed into a relative pronoun, and this is brought to the front of the clause to create the relative clause. Sometimes, however, the noun in the relative clause will be the object of a preposition.

This guide and a number of relative clauses with prepositions activities are available to download as PDF documents.

Look at the following pair of main clauses, for example:

• David met a woman. You used to live with the woman.

Here, we have two pieces of information about ‘the woman’, but in the second sentence, ‘the woman’ is the object of the preposition ‘with’. If we want to add information to ‘the woman’ in the first sentence, we need to convert the second sentence into a relative clause.

We know that to do this, we need to change ‘the woman’ into a relative clause, which in this case could either be that or whom (as ‘the woman’ is the object of a preposition). We also know that the relative pronoun needs to be brought to the front to introduce the relative clause.

However, this causes a lot of confusion over where to put the preposition – does it stay where it is after the verb ‘live’, or does it move to the front of the relative clause still connected to its object? We can actually do both in English, but we need to be aware of the different grammar rules and the different level of formality.

The informal (common) structure

Informally, and therefore more commonly, we would leave the preposition after the verb where it would usually appear. In this case, all we have to do it move that or whom to the front of the clause as usual and leave ‘with’ where it is:

• David met a woman whom you used to live with.

With that said, as this is informal English, it would be much more common to use who instead of whom:

• David met a woman who you used to live with.

As these types of relative clauses will always be object relative clauses (as the relative pronoun represents the object of a preposition), we can omit the relative pronoun as usual if the clause is a defining relative clause (if the clause is non-defining, we cannot omit the relative pronoun):

• David met a woman (who) you used to live with.

The formal (less common) structure

The formal way involves keeping the preposition connected to its object, now transformed into a relative pronoun, by moving it to the front of the clause. We cannot use the relative pronoun that in this structure, only which or whom (as this is formal, and as we are talking about the object of a preposition, we would probably not use who in this structure):

• David met a woman with whom you used to live.

When following the formal structure and placing the preposition before which or whom, you cannot omit either the preposition or relative pronoun, regardless of whether it is defining or non-defining.

Relative clauses with prepositions examples

Here are some more examples:

• The hotel was excellent. We stayed in the hotel.
  • Informal: The hotel (that) we stayed in was excellent.
  • Formal: The hotel in which we stayed was excellent.

• They decided on the plan. The plan hasn’t worked.
  • Informal: The plan (that) they decided on hasn’t worked.
  • Formal: The plan on which they decided hasn’t worked.

• I saw my friend yesterday. I went to university with my friend.
  • Informal: I saw my friend, who I went to university with, yesterday.
  • Formal: I saw my friend, with whom I went to university, yesterday.

• Maria listens to music. The music is terrible.
  • Informal: The music (that) Maria listens to is terrible.
  • Formal: The music to which Maria listens is terrible.

• Helen didn’t like the house. Helen looked at the house.
  • Informal: Helen didn’t like the house (that) she looked at.
  • Formal: Helen didn’t like the house at which she looked.

• Do you remember that thing? Martin was talking about the thing.
  • Informal: Do you remember that thing (that) Martin was talking about?
  • Formal: Do you remember that thing about which Martin was talking?

Relative adverbs

When the prepositional phrase in the relative clause refers to a location or time, we also have the option of using a relative adverb instead of the formal and informal structures above. We use the relative pronouns where for locations, and when for times, and when this is possible, it is probably more common than using the structures above. You can read more about relative pronouns with relative adverbs here.

Here are some examples of when we might use a relative adverb instead of a relative pronoun if the object of the preposition in the relative clause refers to a location or time:

• We visited the restaurant. Your son works in the restaurant.
  • We visited the restaurant that your son works in. (relative pronoun, informal)
  • We visited the restaurant in which your son works. (relative pronoun, formal)
  • We visited the restaurant where your son works. (relative adverb, more common)

• I’ll meet you at the place. I met you at the place last time.
  • I’ll meet you at the place that I met you at last time. (relative pronoun, informal)
  • I’ll meet you at the place at which I met you last time. (relative pronoun, formal)
  • I’ll meet you at the place where I met you last time. (relative adverb, more common)

• They will never forget the day. They got married on that day.
  • They will never forget the day that they got married on. (relative pronoun, informal)
  • They will never forget the day on which they got married. (relative pronoun, formal)
  • They will never forget the day when they got married. (relative adverb, more common)

• People still talk about the moment. He arrived at that moment.
  • People still talk about the moment that he arrived at. (relative pronoun, informal)
  • People still talk about the moment at which he arrived. (relative pronoun, formal)
  • People still talk about the moment when he arrived. (relative adverb, more common)

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