Learn Hardcore Spanish (Spain): En nuestra amistad, no aceptamos que nadie falte al respeto a otra persona. - In our friendship, we do not accept anyone disrespecting another person.

aceptamos que + indicativo → we accept that something is a fact
- Aceptamos que Juan llega tarde. (We accept that Juan arrives late.)
no aceptamos que + subjuntivo → we do not accept / do not allow that something happens
- No aceptamos que nadie falte al respeto… (We don’t accept / allow anyone to be disrespectful…)

Negating aceptamos turns it into a kind of judgment / will / prohibition, which is one of the classic triggers for the subjunctive.

So:

que nadie falte al respeto = that nobody be disrespectful
Using falta here would sound ungrammatical to a native speaker.

Why do we have both no and nadie? Isn’t that a double negative?

Yes, it is a double negative in English terms, but in Spanish this is normal and required. Spanish uses negative concord:

When the sentence is negative, and you use words like nadie, nada, nunca, etc., you usually also include no before the verb.

Examples:

No viene nadie.
(Literally: Not comes nobody → Nobody is coming.)
No veo nada.
(I don’t see anything.)
No aceptamos que nadie falte al respeto.
(We don’t accept that anybody disrespects someone.)

If you removed no and only said:

Aceptamos que nadie falte al respeto…

it would mean something different and sound strange: We accept that nobody is disrespectful… (stating a fact, not a rule).

What exactly does faltar al respeto mean? Is it literally “to lack respect”?

Literally, yes: faltar al respeto is like “to be missing with respect” → to fail in respect.

Idiomatic meaning: to be disrespectful to someone, to speak or act disrespectfully toward someone.

Common uses:

No le faltes al respeto a tu madre.
Don’t be disrespectful to your mother.
El alumno le faltó al respeto al profesor.
The student was disrespectful to the teacher.

It’s a set expression in Spanish. While there is a verb disrespect in English, in Spanish disrespetar is not standard in this sense; people almost always say faltar al respeto (a alguien) or tener una falta de respeto.

Why is it al respeto and not el respeto?

Al is just the normal contraction of a + el:

a + el respeto → al respeto

In the expression faltar al respeto, the preposition a is required by the verb faltar in this idiom:

faltar a algo → to fail in / to not respect something
Here: faltar al respeto → to fail in respect.

So grammatically:

faltar (verb)
a (preposition)
el respeto (noun phrase)
a otra persona (who the disrespect is towards)

You must say al respeto in this expression; faltar el respeto would be incorrect.

Why is there another a in a otra persona? Isn’t a already used with al respeto?

They’re two different a’s doing two different jobs:

al respeto
- a = preposition governed by the verb faltar in this idiom
- el respeto = the noun it goes with
a otra persona
- This is the “personal a” used before a person (or people) who is the object of the action:
  - Veo a María.
  - Escucho a los niños.
- In this idiom, the full pattern is:
  - faltar al respeto a alguien

So the structure is:

faltar
al respeto (to respect, in general)
a otra persona (to another person – the person we are disrespecting)

Why is nadie singular, and why does the verb agree as falte (singular)? Could it be plural?

Nadie is grammatically singular in Spanish, even though it refers to an unlimited set of people (“no one / nobody / anybody”).

Nadie viene. (Nobody comes.)
Nadie falte al respeto. (No one be disrespectful.)

So the verb is 3rd person singular: falte.

If you want an explicitly plural idea, you’d normally change the noun:

Ninguna persona falta / falte al respeto. (No person…)
Ningunas personas… – technically possible but very unnatural; people rarely say this.

In practice, nadie + singular verb is the standard way to say “nobody / no one / anyone” in negative contexts.

Why is it a otra persona and not a nadie at the end?

The choice changes the nuance:

a otra persona
→ to another person
Emphasizes that in this friendship/group, no one should disrespect any other individual. It sounds like a rule about how we treat each other (or others in general).
a nadie
→ to nobody / to anyone
No aceptamos que nadie falte al respeto a nadie.
This would mean: We don’t accept anybody being disrespectful to anyone (at all).
It sounds more absolute and slightly more abstract.

The original a otra persona feels more concrete and “inside the relationship”: within our friendship, no one should disrespect another person (in the group or around us).

What’s the role of En nuestra amistad at the beginning? Could it go at the end?

En nuestra amistad is a prepositional phrase meaning “in our friendship / in our relationship”. It sets the context or scope of the rule.

Word order options:

En nuestra amistad, no aceptamos que nadie falte al respeto a otra persona.
(Original, very natural.)
No aceptamos que nadie falte al respeto a otra persona en nuestra amistad.
Also grammatically correct, but heavier at the end and less stylistically neat.

Putting En nuestra amistad at the start gives it emphasis:
“In our friendship, [this is the rule]…”

Could I replace aceptamos with permitimos or toleramos? Would it change the meaning?

Yes, you can, with slight nuances:

No aceptamos que nadie…
→ We don’t accept this; it goes against our values / principles.
No permitimos que nadie…
→ We don’t allow this; sounds more like an explicit rule or authority.
No toleramos que nadie…
→ We don’t tolerate this; a bit stronger, more emotional, zero tolerance.

All are common in Spain:

En nuestra amistad, no permitimos que nadie falte al respeto a otra persona.
En nuestra amistad, no toleramos que nadie falte al respeto a otra persona.

The grammar stays the same: no + [verb of will/judgment] + que + subjunctive.

Why is it nuestra amistad and not la amistad or en la amistad?

Each choice slightly shifts the meaning:

nuestra amistad = our friendship / our relationship
Personal, specific: the friendship between us.
la amistad = friendship (in general)
More general, like a principle:
- En la amistad, no se acepta que nadie falte al respeto…
  (In friendship, you don’t accept anyone being disrespectful…)

Using nuestra amistad makes it clear you’re describing the rules of your own friendship group or relationship, not a general statement about all friendships.

Could I say No aceptamos que falte nadie al respeto a otra persona with nadie after the verb?

You could move nadie, but:

No aceptamos que nadie falte al respeto… is the normal, neutral word order.
No aceptamos que falte nadie al respeto… is possible but sounds:
- more marked / emphatic
- slightly less natural in everyday speech
- like you’re stressing nadie as a surprise: “that anyone at all be disrespectful”.

For learners, it’s best to stick with the standard order:

No aceptamos que nadie falte al respeto a otra persona.

Is this sentence natural in Spain, or would people say something different?

The sentence is perfectly natural in Spain. People might also say very similar variants, such as:

En nuestra amistad, no toleramos que nadie falte al respeto a otra persona.
Entre nosotros no permitimos que nadie falte al respeto a nadie.
En nuestro grupo no aceptamos faltas de respeto.

But your original sentence:

En nuestra amistad, no aceptamos que nadie falte al respeto a otra persona.

sounds correct, idiomatic, and fully natural in Peninsular Spanish.