Ese taburete encaja debajo del escritorio.

Ese means that, while este means this.

In Spanish, the choice often depends on how close the object feels to the speaker:

• este taburete = this stool
• ese taburete = that stool

In modern Spanish, especially in everyday speech, ese is very common for something that is not right next to the speaker.

Taburete usually means stool, especially a seat without a backrest.

It is a masculine noun:

• el taburete
• ese taburete

In Spain, taburete is a very normal word for a stool, such as a kitchen stool or bar stool.

Because taburete is a masculine noun.

Spanish demonstratives must agree with the noun in gender and number:

• este / ese / aquel for masculine singular
• esta / esa / aquella for feminine singular

So:

• ese taburete ✅
• esa taburete ❌

Here, encaja means something like fits or fits into place.

The verb is encajar. Depending on context, it can mean:

• to fit physically
• to slot into place
• to match or suit
• to accept or process something emotionally

In this sentence, it is the physical meaning: the stool fits underneath the desk.

Both can sometimes be translated as fits, but they are not exactly the same.

• caber focuses on whether there is enough space: it fits / there is room
• encajar often suggests that something fits well into a space or position

So:

• Ese taburete cabe debajo del escritorio = That stool fits under the desk / there is room for it
• Ese taburete encaja debajo del escritorio = That stool fits neatly or properly under the desk

In many contexts, either could work, but encaja gives a stronger idea of going into place.

Because the subject is ese taburete, which is he/it in grammatical terms.

The verb encajar is conjugated like this in the present tense:

• yo encajo
• tú encajas
• él/ella/usted encaja
• nosotros encajamos
• vosotros encajáis
• ellos/ellas/ustedes encajan

So ese taburete encaja = that stool fits.

Both can mean under or below, but debajo de is often more explicit and common when talking about physical location.

• debajo del escritorio = underneath the desk
• bajo el escritorio = under the desk

In many situations, they are interchangeable. However:

• debajo de often sounds a bit more clearly spatial
• bajo can sometimes sound slightly more formal or literary, depending on context

For everyday physical placement, debajo de is very natural.

Because de + el contracts to del in Spanish.

So:

• debajo de el escritorio ❌
• debajo del escritorio ✅

This contraction is mandatory with de + el.

A similar contraction happens with a + el = al.

Escritorio usually means desk, while mesa usually means table.

So the choice depends on the piece of furniture:

• escritorio = desk
• mesa = table

If the sentence is about something fitting under a work desk, escritorio is the natural word.

Not normally.

In Spanish, singular countable nouns usually need a determiner such as:

• el
• un
• este
• ese
• mi

So you would normally say:

• Ese taburete encaja debajo del escritorio
• El taburete encaja debajo del escritorio
• Un taburete encaja debajo del escritorio

Just Taburete encaja... sounds incomplete.

Because Spanish usually does not need an explicit subject pronoun when the subject is already stated.

In English, you say:

• That stool fits under the desk

In Spanish, once the noun is there, you just use the verb:

• Ese taburete encaja debajo del escritorio

You would not add a separate word for it.

Yes, but the meaning changes.

• encaja debajo del escritorio = it fits under the desk
• está debajo del escritorio = it is under the desk

So encaja talks about suitability or fit, while está only talks about location.

Usually yes in a neutral sentence, but Spanish word order is flexible.

The most natural order here is:

• Ese taburete encaja debajo del escritorio

You could move things around for emphasis, for example:

• Debajo del escritorio encaja ese taburete

But that is less neutral and more marked. For learners, the original order is the best model.

It sounds perfectly natural in Spain.

A speaker from Spain would understand it as a normal everyday sentence. The vocabulary is especially standard for Spain:

• taburete is common
• escritorio is common
• debajo de is completely natural

So this is a good sentence to learn as standard Peninsular Spanish.