A non-native English learner asked me,

Could you tell me the difference between ”on which, at which, in which” and ”where” as a relative pronoun? i saw them in a question and could not figure out the answer. please have a look:

In the old days when every city had to be well guarded, the ancient city of Basel, in Switzerland, was surrounded by a high wall ……..
there was only one gate.

A) where

B) on which

C) at which

This is an excellent opportunity to explain which and where.

Location, Location, Location

In real estate (that is, the buying and selling of land), a motto heard in English-speaking countries is “location, location, location.” These are said to be the three most important things determining the price of a piece of land. Yes, they repeat “location” three times for emphasis.

Which and where both concern location. However, the two have a major difference between them.

Global Location

Where concerns the location of a place relative to the entire world.

Example: “Where do you live, Jeremiah?” “I live in Nova Scotia, Canada.”

Map of Nova Scotia

It’s All Relative

“Whichdescribes relative to a specific object. In English, specific objects are nouns, so “which” will always refer to nouns. “In which,” “at which,” and “on which” all relate to nouns.

Example: “Which town do you live in?” “I live in Comeauville.”

Continuing the example:

Where on the map is it?” “It is between Meteghan and Church Point.”

On which side of Nova Scotia are Meteghan and Church Point?” “They are on the West side of Nova Scotia.”

As you can see here, where is in relation to the world. “On which,” “at which,” and “in which” are prepositions; they indicate location relative to a specific object, or objects; in this case, relative to the sides of Nova Scotia (North, South, East, and West, for instance).

“Which ___?” is a question that functions in a similar way. A noun must be the answer to a “Which ___?” question.

Also, we use “Which ___?” to ask the listener to indicate which option is correct, from a list of obvious, known options. Nova Scotia has a limited number of sides, so “Which side?” works.

Warning: Don’t confuse this usage of “which” with using “which” or “that” to start a clause. That is a subject for a separate article. Example:

  • The house that I wanted to buy has been sold.
  • The house, which I didn’t want to buy, has been sold.

We’re not touching that today.

Back To The Top

Let us return to the original question.

In the old days when every city had to be well guarded, the ancient city of Basel, in Switzerland, was surrounded by a high wall ……..
there was only one gate.

A) where

B) on which

C) at which

UPDATE: So, the person who posed the question got back to me and specified that his teachers said a) where is the proper answer.

Of course, the issue is not just what the answer is, but why the answer is so. Also, teachers want to see the best answer, not merely an acceptable one.

b) on which, is clearly wrong, because it implies the gate is “on top” of the wall, which it cannot be.

An answer which is not among the three, “in which,” would make some sense, because you can have a door, in which there is a lock.

I am guessing, but cannot be absolutely certain, that this sentence became victim to a plague among grammar teachers called the “You Can’t End A Sentence With A Preposition” rule.

Prepositions at the End of Sentences

Over two hundred years ago, English poets and professors began creating a rule: ending a sentence with a preposition is wrong.

Why is this? Because you can’t in Latin.

No, really, that’s the reason.

Never mind the obvious observation that English is not Latin. For centuries, people had been trying to break English away from its Anglo-Saxon roots. As I have written before, English is a hybrid between Old English and Romance languages (chiefly French) due to the Norman conquest and “English” aristocracy being fluent French speakers descended from inhabitants of Normandy (northern France). Nonetheless, let us not allow this to obscure the real point:

There is no such rule in “real” English.

Unfortunately, there is such a rule in the minds of far too many grammar teachers.

This is, to be blunt, simplistic thinking.

Real English does not require this.

Real English still uses grammar with Germanic roots rather than Latin roots. Take these two examples (found with Google):

There is no need to notify us about problems of which we are already aware.


There is no need to notify us about problems which we are already aware of.

This is not to say that the first example is incorrect; it is acceptable, since Latin rules are acceptable. English is a hybrid language.

This is to say that the second example is also correct, even though it uses Germanic rules. It sounds natural, especially in American English.

Winston Churchill was once scolded about using a preposition to end a sentence. His reply:

That is the sort of thing up with which I will not put!

Rather than, “That is the sort of thing which I will not put up with!”which sounds far more natural.

So, it’s a made-up rule, but the writers and graders of the test question expect us to rule out options b) on which, and c) at which, because they are prepositions, not because of any other reason.

Back To The Question

Honestly, an option not offered, “in which,” would be far more descriptive, provided that the gate was physically constructed to be part of the wall, like a lock is built into a door. To be complaint with the stingy Latin grammar rule, we would have a sentence like this:

“The door, in which rested a lock, opened.”

For a gate to be at a wall, it might be built immediately outside the wall as part of a gatehouse. Gatehouses may or may not have existed in ancient Switzerland, but they certainly existed in medieval times.

Anyway, that isn’t the point.

A) where is considered the correct answer because where is a conjunction, and not a preposition. Therefore, according to the testers, “where” can be used in this sentence, but “which” (or any derivative thereof) cannot.

Final Thoughts

In practice, there is only one reason to ban prepositions from the end of a sentence: when the preposition is redundant. That is nothing personal against prepositions; it is a general rule against redundancy. If no one will miss a preposition disappearing, it isn’t necessary.

By rights, in real English, a preposition is permitted at the end of a sentence if it accomplishes some useful purpose.

I hope this update explains better how teaching English for real life differs a great deal from teaching English for a test, when the test uses a rule that does not exist in real life, nor in linguistics, but solely in the minds of a gang of professors who think that Latin’s inherent superiority to English should dictate that all traces of Germanic grammar structure should die.

Maybe someday, but it’s not dead yet. Real English lives on.