Hay polvo por todo el escritorio.

Hay means there is / there are. It is used to say that something exists or is present somewhere.

So:

• Hay polvo por todo el escritorio = There is dust all over the desk

If you used está, you would normally be talking about the location or state of something more specific:

• El polvo está sobre el escritorio = The dust is on the desk

A useful shortcut:

• hay = existence/presence
• está / están = location/state of something specific

Because the sentence is introducing the presence of dust, hay is the natural choice.

In Spanish, polvo is usually treated as an uncountable noun, just like dust in English.

So Spanish normally says:

• Hay polvo = There is dust

not

• Hay polvos for ordinary dust

The plural polvos exists, but it usually means powders or different kinds of powder, not everyday dust on furniture.

Because polvo is being used in a general, uncountable sense.

Compare:

• Hay polvo = There is dust
• Hay el polvo = not natural here

This works like English:

• There is dust on the table
• not normally There is the dust on the table, unless you mean some specific dust already mentioned

So in this sentence, polvo is just general dust, not a specific, previously identified dust.

Por todo el escritorio means all over the desk or throughout the desk surface/area.

Breakdown:

• por = through / around / over, depending on context
• todo el escritorio = the whole desk

Together, por todo el escritorio gives the idea of dust being spread across many parts of the desk, not just in one spot.

It is more natural than a very literal word-for-word translation. Spanish often uses por todo + place to mean all over:

• por toda la casa = all over the house
• por toda la ciudad = all over the city

Because when todo means the whole / all the, Spanish normally uses the definite article:

• todo el escritorio = the whole desk / all the desk
• toda la casa = the whole house

Without the article, the meaning changes:

• todo escritorio would mean something more like every desk, which does not fit here

So:

• por todo el escritorio = all over the desk
• not por todo escritorio

Yes, un escritorio is grammatically possible, but it changes the feel.

• el escritorio = the desk, usually a specific desk known from the situation
• un escritorio = a desk, some desk

So:

• Hay polvo por todo el escritorio suggests a specific desk the speaker and listener can identify
• Hay polvo por todo un escritorio sounds more indefinite and less natural in many everyday situations

In normal conversation, if both people know which desk is meant, el escritorio is the most natural choice.

The usual and most natural order is:

• Hay polvo por todo el escritorio

This follows a very common Spanish pattern:

• hay + noun + place/expression

You could sometimes move things around for emphasis, but it may sound less neutral:

• Por todo el escritorio hay polvo

This is still correct, but it puts more focus on por todo el escritorio. It can sound a bit more descriptive or emphatic.

So for a learner, the safest default is:

• Hay + thing + location

Yes, you may hear that, and people would understand it, but por todo el escritorio is usually better for all over the desk.

Why?

• en often just means in / on / at
• por todo gives a stronger sense of being spread around across many parts

So:

• Hay polvo en el escritorio = There is dust on the desk
• Hay polvo por todo el escritorio = There is dust all over the desk

The second one sounds more vivid and more natural for this idea.

In standard Spanish, hay is pronounced roughly like eye in English.

A few pronunciation notes:

• h is silent in Spanish
• ay sounds like the vowel sound in eye

So:

• hay ≈ eye

The full sentence is approximately:

• eye POL-bo por TO-do el es-kree-TOR-yo

A more Spain-oriented pronunciation guide:

• hay = ai
• polvo = POL-bo
• escritorio = es-kree-TOR-yo

In Spain, escritorio commonly means desk, especially a writing desk or office desk.

For office, the usual word is:

• oficina

So:

• escritorio = desk
• oficina = office

This is important because English learners sometimes confuse them due to the similarity between escritorio and escrito or because some related words in other languages mean something closer to office.

In this sentence, escritorio clearly means desk.

Yes. That is a very natural alternative, but it is slightly different in structure and emphasis.

• Hay polvo por todo el escritorio = There is dust all over the desk
• El escritorio está lleno de polvo = The desk is covered in dust / The desk is full of dust

The first sentence focuses on the presence of dust. The second focuses on the condition of the desk.

Both are natural. The version with hay is especially useful because it teaches the common pattern for saying that something is present somewhere.

Yes. Literally, polvo means dust or sometimes powder, depending on context.

Examples:

• polvo = dust
• polvo de azúcar = powdered sugar
• polvo facial = face powder

One thing to be aware of: in colloquial Spanish, especially in some contexts, polvo can also have a slang meaning. But in a sentence like Hay polvo por todo el escritorio, the meaning is clearly the normal one: dust.

For a learner, the main meaning to remember here is simply dust.