Learn Hardcore Spanish (Latin America): Puedes elegir cualquier asiento en el auditorio. - You can choose any seat in the auditorium.

Puedes = you (informal singular, tú): “You can choose...”
Puede = you (formal singular, usted) or he/she/it: “You (sir/ma’am) can choose...”
For a group: pueden (ustedes): “You all can choose...”
In voseo areas (e.g., Argentina): vos podés.

Examples:

Informal: Puedes elegir cualquier asiento...
Formal: Puede elegir cualquier asiento...
Plural: Pueden elegir cualquier asiento...
Voseo: Podés elegir cualquier asiento...

Does puedes express permission or ability here?

Both are possible with poder, but in this context it clearly gives permission (“You may choose any seat”). Poder can also mean ability (“You can lift this”), but context disambiguates.

Could I say Elige cualquier asiento en el auditorio instead?

Yes. Elige... is a direct imperative (“Choose any seat...”), more direct than Puedes elegir.... Options:

Informal command: Elige...
Formal command: Elija...
Plural command: Elijan...

Commands are concise; Puedes elegir... sounds friendlier/less bossy.

Why usar elegir and not escoger? Are they different?

Elegir and escoger both mean “to choose,” and you can use either:

Puedes elegir/escoger cualquier asiento... Nuance: elegir can feel a touch more formal; escoger is very common. Avoid coger in many Latin American countries because it’s vulgar there. Another natural option is tomar asiento (“to take a seat”).

How do you conjugate elegir in the present?

It’s irregular: e → i, and the yo-form changes g → j.

Yo elijo
Tú eliges
Él/Ella/Usted elige
Nosotros elegimos
Ustedes/Ellos eligen
Voseo: Vos elegís Preterite reference: eligió, eligieron.

Why is it cualquier and not cualquiera?

Before a singular noun, use the invariable determiner cualquier:

cualquier asiento, cualquier mesa As a pronoun (not followed by a noun), use cualquiera:
Puedes elegir cualquiera de los asientos.

Does cualquier agree in gender/number?

In the singular before a noun, cualquier doesn’t change for gender: cualquier asiento/mesa.
The traditional plural is cualesquiera (formal/rare): cualesquiera asientos. In modern usage, people usually say cualquiera de los asientos instead. Don’t say “cualquier asientos.”

What’s the difference between cualquier asiento and asiento cualquiera?

cualquier asiento = any seat (no matter which).
asiento cualquiera = a random/ordinary seat, with a “nothing special” nuance. It doesn’t give permission; it describes the seat.

Why is there no a before cualquier asiento?

Elegir takes a direct object without a preposition for things: elegir un asiento. The personal a appears before animate direct objects:

Elegimos a Marta (we elected Marta).
Elegimos un asiento (we chose a seat).

What’s the difference between asiento, silla, and butaca?

asiento: “seat” in general (the place to sit).
silla: a chair (a piece of furniture with legs/back).
butaca: a padded, numbered theater/cinema seat. In an auditorium, butaca is often the most precise.

Does auditorio mean the building or the audience?

Here it’s the building/room (auditorium). For the people, Latin America commonly uses público or audiencia. Auditorio can mean “audience” in some contexts, but en el auditorio clearly refers to the place.

Why en el auditorio and not del or al?

en = in/inside: en el auditorio = “in the auditorium.”
del = “of the/from the.”
al = “to the” (contraction of a + el). Not needed here.

Can I move en el auditorio to the beginning?

Yes: En el auditorio, puedes elegir cualquier asiento. Same meaning; fronting the location adds emphasis to the setting.

If I just want to tell someone to sit anywhere, what could I say?

Natural options:

Puedes sentarte en cualquier asiento.
Informal command: Siéntate en cualquier asiento.
Formal: Siéntese en cualquier asiento.

Any pronunciation tips for elegir and related forms?

In elegir, the g before i sounds like Spanish j (a harsh “h”): approx. eh-le-HEER.
To keep that sound in the yo form, spelling changes to elijo (with j): eh-LEE-ho.
auditorio is stressed on “to”: au-di-TO-rio.

How do I say this to a group or politely?

Polite singular (usted): Puede elegir cualquier asiento... or Elija cualquier asiento...
Group (ustedes): Pueden elegir... or Elijan...
Voseo regions: Podés elegir... (vos) / plural still Pueden...

Is there any trickiness with negatives like “You can’t just choose any seat”?

Yes. No puedes elegir cualquier asiento can mean “You can’t just pick any seat (you like)—there are restrictions.” Another useful structure is:

No cualquiera puede sentarse aquí. = “Not just anyone can sit here.”