Después del apagón, mi madre buscó un alargador y enchufó la regleta en otro sitio.

Because de + el normally contracts to del in Spanish.

So:

• de el apagón → del apagón

This is a standard rule:

• la puerta del coche
• después del apagón
• vengo del trabajo

A common exception is when El is part of a proper name, such as de El Escorial.

Because después normally takes de when it is followed by a noun, pronoun, or infinitive.

Examples:

• después del apagón = after the blackout
• después de eso = after that
• después de comer = after eating

If después appears on its own, it usually means afterwards or later:

• Primero comemos y después salimos.

They are in the preterite because the sentence tells a sequence of completed actions in the past:

• she looked for an extension lead
• she plugged in the power strip somewhere else

That is exactly the kind of situation where Spanish often uses the preterite.

Forms:

• buscó = he/she looked for
• enchufó = he/she plugged in

If the sentence were describing an ongoing background situation instead, Spanish might use the imperfect, but here the actions are presented as single completed events.

The accent mark shows both pronunciation and meaning.

• busco = I look for / I am looking for

• buscó = he/she looked for

• enchufo = I plug in
• enchufó = he/she plugged in

So the accent on the final -ó marks the third-person singular preterite and also shows that the stress falls on the last syllable.

No. Buscar means to look for.

So mi madre buscó un alargador means she looked for an extension lead, not necessarily that she found it.

If you want to say found, Spanish usually uses encontrar:

• Mi madre encontró un alargador.

This is a very common learner point because English sometimes uses look for and find close together in the same situation, but Spanish keeps them clearly separate.

Because Spanish often omits the subject when it is already clear.

In this sentence, both verbs clearly refer to the same person:

• mi madre buscó...
• y enchufó...

Spanish does not need to repeat mi madre or add ella unless the speaker wants extra emphasis or contrast.

A fuller version would be grammatically possible:

• Después del apagón, mi madre buscó un alargador y mi madre enchufó la regleta...

But that sounds repetitive and unnatural.

In Spain, they usually refer to different things:

• alargador = an extension lead / extension cord
• regleta = a power strip / multi-socket adapter

So in the sentence, your mother first looked for an alargador, and then she plugged in the regleta somewhere else.

That combination makes sense: the extension lead helps reach another place, and the power strip is the thing with several sockets.

Here, la regleta is the direct object: it is the thing being plugged in.

The phrase en otro sitio tells you where she plugged it in.

So the structure is:

• enchufar + thing + en + place

Examples:

• Enchufó el cargador en la pared.
• Enchufé la lámpara en otro enchufe.

In everyday Spanish, you may also hear slightly different ways of saying it, but this structure is perfectly understandable.

Because otro normally does not take the indefinite article un/una before it.

So Spanish says:

• otro sitio
• otra casa
• otros libros

Not:

• un otro sitio
• una otra casa

This is different from English, where another already contains the idea of an + other. In Spanish, otro by itself does that job.

Yes, en otro sitio is natural and means somewhere else / in another place. It is a bit general.

If you want to be more specific, you could say:

• en otro enchufe = in another socket
• en otra toma = in another outlet/connection point

So:

• en otro sitio = broader, less specific
• en otro enchufe = more precise

Both can work, depending on what you want to emphasize.

Yes, it sounds very natural for Spain, especially because of words like alargador and regleta.

In other Spanish-speaking countries, people may use different words, for example:

• extensión for alargador
• other regional terms for regleta

Also, sitio is very common in Spain for place.

So the sentence is fully understandable, but some vocabulary choices are especially characteristic of Spain Spanish.