Learn Hardcore Spanish (Latin America): Baja la escalera con cuidado.

To make it clearly a statement, Spanish would usually add a subject:
Él baja la escalera con cuidado. – He goes down the stairs carefully.
Ella baja la escalera con cuidado. – She goes down the stairs carefully.

Why is there no tú in the sentence? Shouldn’t it be Tú baja la escalera con cuidado?

In Spanish, subject pronouns like yo, tú, él, nosotros are normally omitted unless there is a special reason (emphasis, contrast, clarification).

The command baja already tells you it’s tú (informal you).
Saying Tú baja la escalera con cuidado is grammatically possible but sounds:

Unusual in everyday speech, and
Emphatic, almost like “You, go down the stairs carefully (not someone else).”

So the natural command is simply:
Baja la escalera con cuidado.

Why is it baja and not bajes or baje?

These are different imperative forms:

baja – informal tú command
- Baja la escalera con cuidado. – (you, informal) Go down the stairs carefully.
baje – polite usted command
- Baje la escalera con cuidado. – (you, formal) Go down the stairs carefully.
bajes – negative tú command or present subjunctive
- No bajes la escalera corriendo. – Don’t go down the stairs running.

So baja is used because the sentence is talking to someone in an informal tú way and giving a positive command.

Could I say Baja las escaleras con cuidado instead? What’s the difference between la escalera and las escaleras?

Yes, Baja las escaleras con cuidado is also correct and common.

la escalera – refers to the staircase as a whole structure
las escaleras – literally the stairs, thinking of the individual steps, but in many places it’s just the usual way to refer to a staircase

In everyday Latin American Spanish, both are used and usually understood the same way. Local preference varies:

Some speakers say bajar la escalera
Others say bajar las escaleras

You can use either; both sound natural.

What’s the difference between escalera, escaleras, and escalón?

escalera – a staircase or ladder
- La escalera de la casa – the house’s staircase
- Una escalera de mano – a ladder
escaleras – usually means stairs as a set
- Sube las escaleras. – Go up the stairs.
escalón – a single step
- Cuidado con el último escalón. – Watch out for the last step.

In your sentence, escalera is the staircase as a whole.

Why do we say con cuidado and not something like cuidadosamente?

Both exist, but con cuidado is more natural in everyday speech.

con cuidado – literally with care, very common and neutral
- Used all the time: Maneja con cuidado. – Drive carefully.
cuidadosamente – carefully, but sounds more formal, bookish, or emphatic.

So Baja la escalera con cuidado is the normal, conversational way to say this.
Baja la escalera cuidadosamente is correct but less common in casual speech.

Can I change the word order, like Baja con cuidado la escalera? Is that still correct?

Yes, it’s still correct:

Baja la escalera con cuidado. – most natural, very common
Baja con cuidado la escalera. – also correct; sounds a bit more marked or stylistic

Spanish word order is flexible, but the original order is the one you’ll hear most often in this type of instruction.

Does baja here mean go down or lower (like lower something)?

The verb bajar can be:

Intransitive: go down / come down
- Baja la escalera. – Go down the stairs.
Transitive: lower something
- Baja la caja. – Lower the box / Bring the box down.

In Baja la escalera con cuidado, it’s intransitive: go down.
You’re not lowering the staircase; you are going down it.

Sometimes I see bájate instead of baja. What’s the difference?

Bájate is the reflexive version of the command: baja + te.

Baja. – Go down.
Bájate. – Get down / Get off (from something).

Use bájate when the idea is get down from a place (car, bus, chair, bed, etc.):

Bájate del autobús. – Get off the bus.
Bájate de la mesa. – Get down from the table.

With stairs, you most often just say:

Baja la escalera con cuidado. – Go down the stairs carefully.

Using bájate la escalera is either wrong or very nonstandard in most varieties.

How would this sentence change if I wanted to be formal and polite?

Use usted commands and optionally add por favor:

Baje la escalera con cuidado. – (Formal) Go down the stairs carefully.
Por favor, baje la escalera con cuidado. – Please go down the stairs carefully.

Notice the change from baja (tú) to baje (usted).

How would I say Don’t go down the stairs so fast using this structure?

For negative tú commands, use no + subjunctive form:

No bajes la escalera tan rápido. – Don’t go down the stairs so fast.

Or with las escaleras:

No bajes las escaleras tan rápido.

Is there anything special about pronunciation in Baja la escalera con cuidado?

A few points for Latin American Spanish:

baja – j sounds like a strong h in English “house”: [BA-ha].
escalera – the c before a is a k sound: [es-ka-LE-ra].
cuidado – cui sounds like kwee: [kwee-DA-do].

Word stress:

BA-ja
es-ca-LE-ra
cui-DA-do

Everything flows together smoothly: BA-ja la es-ca-LE-ra con cui-DA-do.

Are there other common ways to express a similar warning?

Yes, some frequent alternatives in Latin American Spanish:

Ten cuidado al bajar la escalera. – Be careful when going down the stairs.
Baja despacio la escalera. – Go down the stairs slowly.
Baja con cuidado por las escaleras. – Go down the stairs carefully.
Cuidado al bajar las escaleras. – Careful when going down the stairs.

All keep the same basic idea, just with different structures.