at which

Meanings

1. 1phrasefixed phrase

   In or at a particular place, point, or event; used to introduce a relative clause that gives more information about a location or situation.

   Grammar: Introduces a relative clause; the preposition 'at' is required by the verb or adjective in the clause, e.g., 'the point at which we stop'.

   Patterns

   • noun + at which + clause
   • the point at which
   • the place at which
   • the time at which

   The restaurant at which we ate last night was very expensive.

   This is the exact spot at which the accident happened.

   She described the moment at which she realized her mistake.

2. 2phrasefixed phraseformal

   Used to refer to a specific time or moment when something happens, especially in formal contexts.

   Grammar: Often follows nouns like 'time', 'moment', 'point' to introduce a clause specifying when.

   Patterns

   • the time at which
   • the moment at which
   • the hour at which

   The time at which the meeting will begin has not been decided.

   We need to know the exact moment at which the alarm went off.

   He asked about the day at which the project would be completed.

Common combinations

the point at which

The point at which the two lines cross is the solution.

the place at which

The place at which we met was a small café.

the time at which

Please tell me the time at which you will arrive.

the moment at which

The moment at which she spoke was captured on video.

Synonyms and how they differ

where

More common in everyday speech, but less formal; 'at which' is preferred in writing when the preposition is needed.

when

Used for time; 'at which' can also refer to time but is more formal and precise.

Commonly confused: at which or which? at which or in which?

Practice

Make it your own

Write a sentence using “at which”, then check it and compare it with the examples above.

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