Learn Hardcore Spanish (Spain): Esta zona es peatonal, así que no pueden entrar coches. - This area is pedestrian, so cars cannot enter.

Peatón = pedestrian (a person).
Peatonal = pedestrian-only / for pedestrians. It’s an adjective used with nouns: zona peatonal, calle peatonal. Plural: peatonales (e.g., calles peatonales).

Why is it es peatonal with ser, not está peatonal with estar?

Because this is a classification (the area’s inherent type), so Spanish uses ser. Está peatonal is not idiomatic. If you wanted a result-of-action/state idea, you could say está peatonalizada or se ha peatonalizado.

Why Esta without an accent and not Está?

Esta (no accent) is the demonstrative “this,” agreeing with the feminine zona.
Está (with accent) is the verb “is” from estar.
Example contrast: Esta zona vs. La zona está…

What does así que mean here, and is the comma before it correct?

Así que means “so/therefore,” expressing a consequence. A comma before it is standard: …, así que …. You could also use por eso, por lo tanto, por tanto, or de modo que; así que is a bit more informal in tone.

Who is the subject of pueden entrar?

Coches is the subject, placed after the verb. Spanish often uses postverbal subjects. No pueden entrar coches = Los coches no pueden entrar.

Why is it pueden entrar (infinitive) and not pueden entran?

After a modal verb like poder, Spanish uses the infinitive: pueden entrar (“can enter”). Conjugating both verbs (pueden entran) is ungrammatical.

Can I say No pueden entrar los coches?

Yes. It’s fine and still generic (“cars can’t enter”). You can also front the subject for clarity: Los coches no pueden entrar.

Can I say No puede entrar coches?

No. The verb must agree with the plural subject: No pueden entrar coches. If you want singular, say No puede entrar ningún coche.

Do I need a preposition after entrar here?

Not here, because coches is the subject, not a place. With places, Spain typically uses entrar en: entrar en la zona (some American varieties use entrar a). For means of transport: entrar en coche = “to enter by car.”

Why is there no article before coches?

In prohibitions/rules, Spanish often uses a bare plural for a generic class: No se admiten perros, No pueden entrar coches. Using los coches is also possible and still generic; unos coches would mean “some (particular) cars,” which isn’t intended.

Could I use an impersonal or passive-style phrasing?

Yes:

No se permite la entrada de coches.
No se permiten coches.
No se puede entrar en coche.
On signs: Prohibida la entrada de coches / Se prohíbe la entrada de vehículos.

Is coche the right word in Spain? What about other regions?

In Spain, coche is the standard word for “car.” In much of Latin America, you’ll hear carro; in the Southern Cone, auto. A neutral option on signs is vehículo(s). Note: in Spain, carro usually means “cart/trolley.”

Can I change the clause order or use other connectors?

Yes:

Como esta zona es peatonal, no pueden entrar coches.
Esta zona es peatonal. Por eso no pueden entrar coches.
Esta zona es peatonal; por tanto, no pueden entrar coches.

How do I say it more emphatically, like “not a single car”?

Use ningún: No puede entrar ningún coche or Ningún coche puede entrar.

Any agreement or gender pitfalls with zona?

Zona is feminine: esta zona, not este zona. Adjectives agree: zona peatonal; plural: estas zonas son peatonales (note the plural in -ales).

What’s the difference between No pueden entrar coches and No entran coches?

No pueden entrar coches states a rule/prohibition (“cars aren’t allowed”).
No entran coches states a fact/habit (“cars don’t enter”), which might be because of the rule or for some other reason.

Why does así have an accent?

It’s stressed on the last syllable and ends in a vowel (an “aguda”), so it takes a written accent: así. There’s no standard word asi without the accent.