Learn Hardcore French: Le banc sur lequel nous attendons est propre. - The bench on which we are waiting is clean.

où can refer to a place and often replaces préposition + lequel when the preposition is à or dans, and quite often even with sur in everyday speech.

sur lequel is a bit more explicit and slightly more formal/literary. It literally means on which and matches the English structure.

So you can use:

Le banc où nous attendons… (more common in speech)
Le banc sur lequel nous attendons… (more formal/precise)

Both are correct.

Why is it lequel and not qui or que?

Because in French, after a preposition (like sur, avec, pour, etc.), you normally use lequel / laquelle / lesquels / lesquelles or qui (for people), not que.

lequel replaces a masculine singular thing and comes after the preposition: sur lequel.
qui after a preposition is used only for people: la personne avec qui je parle.

You cannot say:

✗ le banc sur qui nous attendons (banc is not a person)
✗ le banc sur que nous attendons (que cannot follow a preposition)

So lequel is required: sur lequel.

What is lequel agreeing with, and what would the other forms be?

lequel must agree in gender and number with the noun it refers to.

Here it refers to le banc (masculine, singular), so we use:

lequel → sur lequel

Other forms:

Masculine singular: lequel → sur lequel
Feminine singular: laquelle → sur laquelle
- La chaise sur laquelle nous attendons…
Masculine plural: lesquels → sur lesquels
- Les bancs sur lesquels nous attendons…
Feminine plural: lesquelles → sur lesquelles
- Les chaises sur lesquelles nous attendons…

Could I say Le banc où nous attendons est propre instead? Is there any difference?

Yes, you can say:

Le banc où nous attendons est propre.

Differences:

où is shorter and more common in everyday conversation.
sur lequel is more explicit (literally on which) and a bit more formal or written.

In meaning, in this sentence, they are essentially the same: the bench where we are waiting / the bench on which we are waiting.

Why is the word order sur lequel nous attendons and not nous attendons sur lequel?

In a French relative clause, the relative pronoun (here sur lequel) comes right after the noun it refers to, and before the rest of the clause:

Le banc [sur lequel nous attendons] est propre.

The structure is:

antecedent (le banc)
- relative pronoun (sur lequel)
  - subject (nous)
    - verb (attendons)

Nous attendons sur lequel is not allowed, because the relative pronoun must introduce the relative clause; it cannot be left at the end like in English questions (What are you waiting on?).

Why is it attendons on its own and not attendons pour like “wait for”?

In French, attendre already means to wait for. It is a direct transitive verb:

attendre quelqu’un = to wait for someone
attendre le bus = to wait for the bus

You do not add pour:

✗ attendre pour quelqu’un (wrong, unless it means “to wait in order to [do something for someone]” in a very specific context)

In this sentence, attendons has no object expressed (it’s just we are waiting), so it stands alone:

nous attendons = we are waiting

Why is it le banc and not la banc? How do I know the gender?

In French, every noun has a grammatical gender that you must memorize.

The word banc (bench) is masculine, so it takes le:

le banc = the bench

There is no reliable rule to guess the gender of banc from its ending; you simply have to learn it. Dictionaries always show the gender:

banc, n. m. (nom masculin) → masculine noun

Why is propre at the end, after est, and not before banc?

In this sentence, propre is a predicate adjective, linked to the subject by the verb être:

Le banc est propre. → The bench is clean.

French order here is the same as in English: subject + être + adjective.

If you put propre before the noun (un propre banc), it doesn’t mean a clean bench. propre before a noun usually has a different meaning (“own”):

mon propre banc = my own bench

So after être, propre means clean.

Does propre always mean “clean”?

No. propre has two main meanings, depending on its position:

After the noun or after être → usually clean
- un banc propre = a clean bench
- Le banc est propre. = The bench is clean.
Before the noun → often own
- son propre banc = his/her own bench

In the sentence Le banc sur lequel nous attendons est propre, it is after être, so it clearly means clean.

Why is attendons in the simple present and not something like “are waiting”?

French uses the simple present very often where English uses the present continuous:

nous attendons = we wait / we are waiting

If you really want to emphasize the ongoing nature of the action, you can say:

nous sommes en train d’attendre = we are in the middle of waiting

So you could (more emphatically) say:

Le banc sur lequel nous sommes en train d’attendre est propre.

But in most cases nous attendons is perfectly natural and covers we are waiting.

Could I leave out nous and just say sur lequel attendons?

No. In French, subject pronouns like je, tu, il, nous, vous, ils are normally required and cannot be omitted:

sur lequel nous attendons ✅
✗ sur lequel attendons (wrong)

French is not a “pro-drop” language like Spanish or Italian; you almost always need to state the subject pronoun.