Learn Hardcore Spanish (Spain): Me siento en el suelo cuando no hay silla. - I sit on the floor when there is no chair.

I’ve seen sentir, sentarse, and sentirse in dictionaries. They all give me siento as a form. In this sentence, how do I know me siento means I sit (down) and not I feel?

Spanish has three related verbs:

sentir = to feel (something): Siento frío – I feel cold.
sentirse = to feel (a certain way, reflexive): Me siento cansado – I feel tired.
sentarse = to sit down: Me siento en la silla – I sit (down) on the chair.

All three can produce the form me siento, but the meaning is decided by what comes after:

With an adjective: Me siento cansado / mal / feliz → this is sentirse (I feel tired / bad / happy).
With a direct object (no en): Siento frío / siento tu dolor → this is sentir (I feel cold / I feel your pain).
With en
- a place or surface: Me siento en el suelo / en la silla / en el sofá → this is sentarse (I sit (down) on the floor / on the chair / on the sofa).

In Me siento en el suelo cuando no hay silla, the en + el suelo clearly points to sentarse: I sit (down) on the floor….

Why does Spanish use the reflexive me in me siento, when English just says I sit?

In Spanish, sentarse is a reflexive verb: literally “to sit oneself (down).”

Because it’s reflexive, you must use the reflexive pronoun:

Yo me siento (I sit down)
Tú te sientas
Él/ella se sienta
Nosotros nos sentamos
Vosotros os sentáis (Spain)
Ellos se sientan

If you drop the reflexive pronoun:

Siento is no longer from sentarse; it’s from sentir = I feel / I regret.
- Siento el suelo = I feel the floor. (touching it), not I sit on the floor.
- Siento en el suelo is just wrong.

So in standard Spanish, to say I sit (down) you must say me siento.

What’s the difference between me siento, me estoy sentando, and estoy sentado?

All three involve “sitting,” but they focus on different things:

Me siento en el suelo
- Simple present, reflexive.
- Can mean:
  - I sit down on the floor (right now, neutral)
  - I sit on the floor (habitually), which is the meaning in your sentence with cuando.
Me estoy sentando en el suelo
- Present progressive.
- Emphasises the ongoing action: I’m in the process of sitting down on the floor (right this moment).
Estoy sentado en el suelo
- Describes a state/result: I am sitting / I am seated on the floor (I’m already there, not moving).

Your sentence uses me siento because it talks about what you usually do whenever there’s no chair available.

Why is it en el suelo and not something like al suelo or sobre el suelo?

Spanish commonly uses en to mean on when talking about being on a surface:

Me siento en la silla. – I sit on the chair.
Se tumba en la cama. – He lies on the bed.
Se sienta en el suelo. – He sits on the floor.

Details:

en el suelo = on the floor / on the ground (final location).
This is the normal phrase with sentarse.
sobre el suelo = literally on top of the floor; it’s correct but sounds a bit more formal or descriptive. Native speakers in everyday speech would nearly always say en el suelo.
al suelo usually goes with verbs of falling / throwing:
- Se cae al suelo. – He falls to the ground.
- Tiro el vaso al suelo. – I throw the glass to the floor.

With sentarse, the standard construction is sentarse en + surface, so Me siento en el suelo is the natural choice.

Why do we say el suelo with el, but just silla without any article?

Two different things are happening:

el suelo
- We’re talking about that specific floor/ground in the situation, so Spanish uses the definite article:
  - en el suelo ≈ “on the floor” (the floor in this place).
- Saying en suelo (without el) would be wrong here.
(no) hay silla
- With hay (“there is/are”), when you talk about existence in general, you normally don’t use an article with a singular countable noun:
  - Hay silla. (rare in positive, more often with adjectives, e.g. hay silla libre)
  - No hay silla. – There is no chair / there aren’t any chairs.
- Using la silla with hay (e.g. no hay la silla) is ungrammatical in this context.
  To talk about a specific chair, you’d switch to estar:
  - La silla no está. – The chair isn’t (here).

So:

en el suelo: specific known surface → definite article.
no hay silla: general existence of chairs → no article.

Can I say cuando no hay una silla or cuando no hay ninguna silla instead of cuando no hay silla? Do they change the meaning?

All three are grammatically correct, but they sound slightly different:

cuando no hay silla
- Most neutral and colloquial.
- Roughly: when there is no chair / when there are no chairs (available).
cuando no hay una silla
- Sounds a bit more like when there isn’t a single chair or when there isn’t a chair (at all).
- Slightly more specific about “a (single) chair,” but still natural.
cuando no hay ninguna silla
- Very explicit: when there is no chair whatsoever / not even one chair.
- Adds emphasis to the absence.

In everyday speech in Spain, cuando no hay silla or cuando no hay ninguna silla would be the most common choices. Your original version is perfectly normal.

Why is hay used in no hay silla instead of está, as in no está silla?

Spanish distinguishes between:

haber (in the form hay) = there is / there are
Used to talk about existence of something, usually indefinite or unspecified things.
estar = to be (located)
Used to talk about the location of specific, known things.

Compare:

No hay silla.
- There is no chair / There are no chairs (available).
- We don’t care which chair; we mean no chair(s) exist in this situation.
La silla no está (aquí).
- The chair isn’t (here).
- We refer to a particular, already known chair (la silla).

So in cuando no hay silla, we’re talking about the existence or availability of any chair, so hay is the correct verb.

Can I change the word order to Cuando no hay silla, me siento en el suelo? Does that change the meaning?

Yes, you can, and the meaning stays essentially the same.

Both are correct:

Me siento en el suelo cuando no hay silla.
Cuando no hay silla, me siento en el suelo.

The only difference is a slight change in emphasis:

Starting with Cuando no hay silla puts a bit more focus on the condition (the lack of a chair).
Starting with Me siento en el suelo sounds a bit more like a simple statement of what you do, with the condition added after.

This is very similar to English:
I sit on the floor when there’s no chair vs. When there’s no chair, I sit on the floor.

Why is the present tense used after cuando (cuando no hay silla, me siento…)? When would I need the subjunctive, like cuando no haya?

Spanish uses different moods with cuando depending on the meaning:

Habitual / general statements → present indicative
Your sentence is about what you usually do in general:
- Me siento en el suelo cuando no hay silla.
  I sit on the floor when there is no chair (in general / whenever that happens). Here hay and me siento are both present indicative.
Future, one-time or hypothetical events → usually present subjunctive after cuando
- Cuando no haya silla, me sentaré en el suelo.
  When there is no chair (on that future occasion), I will sit on the floor.
- Cuando llegue Juan, hablaremos.
  When Juan arrives, we’ll talk.

So:

For general habits: cuando + present indicative (as in your sentence).
For specific future events not seen as habitual: cuando + present subjunctive.

In Spain, what’s the difference between suelo and piso? Could I say Me siento en el piso?

In Spain:

suelo = the surface you stand/walk/sit on → floor, ground.
- Me siento en el suelo. – I sit on the floor.
- El vaso está en el suelo. – The glass is on the floor.
piso = mainly apartment / flat or storey/floor level of a building.
- Vivo en el tercer piso. – I live on the third floor.
- Tengo un piso en Madrid. – I have a flat in Madrid.

Because of this, in Spain Me siento en el piso would sound odd or be understood as I sit in the flat.
To mean “on the floor” in Spain, you should use en el suelo.

(In much of Latin America, piso often means “floor,” but you specifically asked about Spanish from Spain.)

How would I say this sentence in the negative, and where do I put no and me?

To make it negative, no goes before the reflexive pronoun me, and me stays before the verb:

No me siento en el suelo cuando hay silla.
I don’t sit on the floor when there is a chair.

Word order pattern:

No
- me
  - siento
    - (rest of the sentence)

Wrong versions to avoid:

Me no siento… ❌
No siento en el suelo… ❌ (this actually sounds like I don’t feel on the floor…)

So the correct negative form is: No me siento en el suelo cuando hay silla.