No imaginas lo limpio que queda el cuarto cuando paso la aspiradora.

Not really in the usual negative sense. No imaginas... is a very common Spanish way to say You can’t imagine... or You have no idea...

So here no does negate the verb imaginas, but the whole expression works idiomatically as an emphatic opener, not as a serious statement about someone’s inability to imagine things in general.

• Imaginas = you imagine
• No imaginas = you can’t imagine / you have no idea

It is addressed to tú (informal you).

Because the verb is conjugated for tú:

• yo imagino = I imagine
• tú imaginas = you imagine
• usted imagina = you imagine (formal)
• él/ella imagina = he/she imagines

So No imaginas... means the speaker is talking directly to one person informally.

If it were formal, it would be:

• No imagina... = You can’t imagine... (formal)

This is an exclamative structure in Spanish. Lo + adjective + que means something like:

• how + adjective
• how very + adjective
• the extent to which something is + adjective

So:

• lo limpio que queda el cuarto = how clean the room gets / how clean the room looks afterward

It does not mean the clean thing that...

Examples of the same structure:

• No sabes lo difícil que es. = You don’t know how difficult it is.
• Mira lo bonito que está. = Look how pretty it is.

This structure is extremely common in Spanish.

Because quedar here means to end up, to be left, or to turn out after some action.

• El cuarto está limpio = The room is clean
• El cuarto queda limpio = The room ends up clean / is left clean

In this sentence, the speaker is focusing on the result after vacuuming. That is why queda is very natural.

So:

• lo limpio que queda el cuarto = how clean the room gets / how clean the room is left

Using está would sound more like simply describing its state, not emphasizing the result of vacuuming.

Here quedar does not mean to stay with someone or to meet up, which are other common meanings of the verb.

In this sentence, quedar means:

• to be left
• to end up
• to look / turn out

So:

• queda limpio = it is left clean / it ends up clean
• queda muy bien = it looks very good
• la mesa quedó perfecta = the table turned out perfect

Spanish learners often notice that quedar has many meanings, and this is one of the very common ones.

Spanish often uses the definite article where English might not.

• el cuarto = the room

In this sentence, the speaker is talking about a specific room that both speaker and listener can identify from context, even if English might naturally just say the room without much thought.

Also, in Spain, cuarto can mean room, though habitación is also very common. Depending on context, cuarto may sound a little more everyday or slightly more specific.

Not necessarily. Cuarto usually means room. Sometimes context makes it feel like bedroom, but by itself it does not have to mean that.

Possible translations depending on context:

• the room
• the bedroom

If the original meaning shown to the learner says room, that is perfectly fine.

Because the simple present in Spanish is often used for habitual or general actions.

Here the idea is:

• whenever I vacuum
• when I vacuum

So paso is enough.

Spanish uses the progressive (estoy pasando) less often than English does. If you said:

• cuando estoy pasando la aspiradora

it would sound more like while I am vacuuming, focusing on the action in progress at that exact moment.

But in the original sentence, the meaning is more general: every time the speaker vacuums, the room ends up very clean.

Literally, it is something like I pass the vacuum cleaner, but in natural English it means:

• I vacuum
• I run the vacuum cleaner

This is a fixed expression:

• pasar la aspiradora = to vacuum

You may also hear:

• pasar el aspirador in some varieties
• aspirar in some contexts, though that is less everyday for household vacuuming

In Spain, pasar la aspiradora is completely natural.

Because Spanish usually omits subject pronouns when the verb ending already makes the subject clear.

• paso already means I do / I pass
• so yo paso is usually unnecessary

The sentence could say cuando yo paso la aspiradora, but that would add emphasis, for example if contrasting with someone else:

• cuando yo paso la aspiradora, queda mejor que cuando la pasas tú

Without emphasis, Spanish normally leaves yo out.

It can feel like either one in English, depending on context.

Because the sentence is in the present tense and describes a repeated result, it often means:

• when I vacuum
• whenever I vacuum

So the sense is habitual, not just about one single occasion.

Because the normal word order in Spanish is for the verb to come before or naturally with its subject in this kind of structure:

• lo limpio que queda el cuarto

This sounds natural and idiomatic.

Spanish does allow flexible word order, but lo limpio que el cuarto queda would sound unusual and marked here. A learner should treat lo + adjective + que + verb + noun as a very common pattern.

That translation is understandable, but stays is probably not the best choice.

Because of queda, the sentence is really emphasizing the result after vacuuming:

• You can’t imagine how clean the room gets when I vacuum.
• You can’t imagine how clean the room is left when I vacuum.
• You have no idea how clean the room looks after I vacuum.

Stays would suggest that it remains clean over time, which is not the main idea here.

It works perfectly in Spain, and most of it is widely understandable in the Spanish-speaking world.

Some points that fit Spain well:

• pasar la aspiradora is very natural in Spain
• the use of tú in No imaginas is standard informal speech in Spain

Nothing in the sentence would be strange to a Spanish speaker from Spain. Speakers elsewhere would also understand it easily, though some vocabulary preferences may vary slightly by region.

Yes, absolutely. This is a very useful pattern:

• No imaginas lo + adjective + que + verb...

Examples:

• No imaginas lo caro que es. = You can’t imagine how expensive it is.
• No imaginas lo rápido que corre. = You can’t imagine how fast he runs.
• No imaginas lo bien que cocina. = You can’t imagine how well she cooks.
• No imaginas lo contento que está. = You can’t imagine how happy he is.

This is one of the most useful exclamative structures in Spanish.