Si passes el drap per la taula, la pols ja no hi és.

Catalan often drops subject pronouns when the verb ending already makes the subject clear.

So passes by itself means you pass / you wipe and implies tu.

• Si passes el drap... = If you wipe/pass the cloth...
• Tu passes el drap... is possible, but it adds emphasis, like you in English.

Here the sentence is addressed to one person informally: tu.

After si meaning if, Catalan normally uses the present indicative for real or likely conditions.

So:

• Si passes el drap... = If you wipe the cloth... / If you wipe the table...

Not:

• si passaràs... for this meaning

This is very similar to English, where we also say:

• If you do that, ... not
• If you will do that, ...

A detail that often confuses learners: passes looks like a subjunctive form, but in this sentence it is understood as present indicative because of the si conditional structure.

It is second person singular informal — the tu form.

From passar in the present:

• jo passo
• tu passes
• ell/ella passa
• nosaltres passem
• vosaltres passeu
• ells/elles passen

So this sentence is speaking to one person informally.

If you wanted the formal vostè form, it would be:

• Si passa el drap per la taula...

Literally, it means to pass the cloth over the table.

In normal English, that usually corresponds to wipe the table with a cloth.

So passar el drap is a very natural way in Catalan to talk about wiping a surface with a cloth or rag.

Because per often expresses movement along, across, or over a place or surface.

So passar el drap per la taula gives the idea of moving the cloth over the table surface.

Compare:

• per la taula — across/over the table
• sobre la taula — on top of the table, more static
• a la taula — at the table / to the table, not the best choice here

So per is the natural preposition for the action of wiping across a surface.

Catalan uses definite articles more often than English does.

So el drap and la taula can sound natural even where English might say:

• with a cloth
• wipe the table

In context, el drap can mean:

• the specific cloth already understood in the situation, or
• simply the cloth being used for the task

If you said un drap, that would sound more like a cloth, introducing it as less specific.

Ja no means no longer or not anymore.

It marks a change from an earlier situation.

So:

• la pols no hi és = the dust is not there
• la pols ja no hi és = the dust is not there anymore / no longer there

The word ja does not just mean already here. In negative sentences, ja no is a very common combination meaning no longer.

Hi is a locative pronoun. It means something like there, in that place, or on it, depending on context.

Here it refers to the location connected with the table — essentially on the table / there.

So:

• la pols ja no hi és = the dust is no longer there / on it

Without hi, Catalan would usually need to repeat the place more explicitly.

This little word is extremely common in Catalan and often replaces a repeated location.

In Catalan, ser-hi is very commonly used to mean to be there / to be present / to exist in that place.

So no hi és is a very natural way to say:

• it isn’t there
• it’s no longer there

That is why the sentence uses és from ser.

You may also hear things like:

• La pols ja no està a la taula

That can be understandable, but ja no hi és is especially idiomatic and compact.

Yes. La pols is a singular feminine noun meaning dust.

The article shows this clearly:

• la pols

So even though the word ends in -s, it is not plural here.

This is a useful thing to remember in Catalan: a final -s does not always mean a plural noun.

Because si meaning if has no accent.

Catalan distinguishes:

• si = if
• sí = yes

So in this sentence, si is the conjunction meaning if, which is why it is written without an accent.