Learn Hardcore Spanish (Latin America): La ventilación en esa sala es fuerte y mueve las cortinas. - The ventilation in that room is strong and moves the curtains.

In Spanish, all nouns ending in -ción are feminine. That’s why we say la ventilación instead of el ventilación. You’ll see the same pattern in la canción, la información, la estación, etc.

Why do we say esa sala and not esta sala? What’s the difference?

esta means “this” (near the speaker) and esa means “that” (a bit farther away). Use esta sala if you’re in or right next to the room; use esa sala if you’re referring to a room a little farther off or already mentioned.

Why is en used before esa sala instead of a or dentro de?

The preposition en (in/inside) indicates location: en esa sala = “in that room.” a would mean “to/toward” (“voy a la sala” = I go to the room). dentro de also means “inside of,” but Spaniards and Latin Americans usually just use en for rooms.

Is fuerte an adjective or an adverb here? Could we use fuertemente?

Here, fuerte is an adjective describing la ventilación: “the ventilation is strong.” You can’t say es fuertemente because fuertemente is an adverb, and ser needs an adjective. If you want an adverb, you’d change the verb: for example, la ventilación sopla fuertemente (“the ventilation blows strongly”).

Why is the verb mueve in the third-person singular and not plural?

Because the subject is la ventilación (singular). Both verbs—es and mueve—agree with that one subject: la ventilación es fuerte y mueve las cortinas.

What exactly does mueve mean here? Does it mean “move” or “blow”?

Literally, mover means “to move.” In this sentence, it implies the airflow is moving or swaying the curtains. In English you might say “the ventilation moves the curtains” or more naturally, “the airflow is making the curtains sway.”

Why do we say las cortinas with a definite article when in English we sometimes drop “the”?

Spanish often uses the definite article where English doesn’t. las cortinas means “the curtains” in general. Whenever you talk about specific or known objects (even if you mean them generally), Spanish keeps the article.

Could we replace ventilación with corriente de aire?

Yes. corriente de aire (“air current”) is a common synonym. You could say:
• La corriente de aire en esa sala es fuerte y mueve las cortinas.
Just remember corriente is feminine: la corriente.

Why don’t we say la esa sala? Shouldn’t feminine nouns have the article first?

In Spanish, a demonstrative adjective like esa replaces the definite article, so you say esa sala, not la esa sala. You only use the article la when there’s no demonstrative: la sala.