Entrevistamos al copresentador durante la grabación.

Because Spanish uses the personal a before a direct object when that object is a person.

So:

• Entrevistamos al copresentador = we interviewed the co-host

Here, el copresentador is the direct object, and since it is a person, Spanish adds a.

Also, a + el contracts to al:

• a + el = al

So you do not say a el copresentador here.

The personal a is a very common feature in Spanish. When the direct object is a specific person, or sometimes a pet or personified thing, Spanish usually puts a before it.

Examples:

• Veo a María. = I see María.
• Conocemos al profesor. = We know the teacher.
• Entrevistamos al copresentador. = We interviewed / interview the co-host.

English does not do this, so it often feels strange to learners at first.

Because entrevistamos can be either:

• present tense: we interview
• preterite: we interviewed

For -ar verbs, the nosotros form is identical in those two tenses.

So without more context, Entrevistamos al copresentador durante la grabación could mean either:

• We interview the co-host during the recording
• We interviewed the co-host during the recording

Usually context tells you which one is meant.

Compare:

• Hoy entrevistamos al copresentador. = Today we interview the co-host.
• Ayer entrevistamos al copresentador. = Yesterday we interviewed the co-host.

It is the first person plural (nosotros) form of entrevistar.

From entrevistar:

• yo entrevisto
• tú entrevistas
• él/ella entrevista
• nosotros entrevistamos
• vosotros entrevistáis
• ellos entrevistan

And in the preterite:

• yo entrevisté
• tú entrevistaste
• él/ella entrevistó
• nosotros entrevistamos
• vosotros entrevistasteis
• ellos entrevistaron

So entrevistamos is a normal form of entrevistar, but it is ambiguous between present and preterite.

Durante means during and is followed by a noun phrase:

• durante la grabación = during the recording

Mientras means while, and it usually introduces a clause with a verb:

• mientras grababan = while they were recording
• mientras hacíamos la grabación = while we were making the recording

So in your sentence, durante is correct because it is followed by the noun la grabación, not by a conjugated verb.

Spanish often uses the definite article more than English does.

So durante la grabación is the natural way to say during the recording.

Using no article here would sound incomplete or unnatural in most contexts. The article points to a specific recording session or the recording process being referred to.

Copresentador means co-presenter, co-host, or co-anchor, depending on context.

It is made from:

• co- = co-
• presentador = presenter / host

So it refers to someone who presents a programme together with someone else.

In more natural English, you will often translate it as co-host.

Yes. Copresentador is the masculine singular form.

If the co-host is female, you would normally say:

• la copresentadora

So the sentence would become:

• Entrevistamos a la copresentadora durante la grabación.

Notice that here there is no contraction, because:

• a + la = a la
  not al

Only a + el contracts to al.

Yes, absolutely.

Both are correct:

• Entrevistamos al copresentador durante la grabación.
• Durante la grabación, entrevistamos al copresentador.

The second version puts more emphasis on the time expression durante la grabación.

Spanish word order is often more flexible than English, especially with time expressions and other adverbial phrases.

Sometimes, but the meaning is not exactly the same.

• durante la grabación = during the recording, at some point in the course of it
• en la grabación = in the recording / at the recording

Durante focuses on the action happening over the time span of the recording.
En can sound more like location or context.

So for this sentence, durante la grabación is the most precise and natural choice if you mean the interview happened while the recording was taking place.

You could say:

• Nosotros entrevistamos al copresentador durante la grabación.

But Spanish usually drops subject pronouns when they are not needed, because the verb ending already shows who the subject is.

So Entrevistamos already tells you we.

Using nosotros is only necessary if you want emphasis, contrast, or clarity.

For example:

• Nosotros entrevistamos al copresentador, no ellos.
  = We interviewed the co-host, not them.

Grabación is pronounced roughly gra-ba-THYON in much of Spain, or gra-ba-SYON in areas that do not use the th sound.

The written accent on -ción shows that the stress falls on the last syllable:

• gra-ba-CIÓN

Without the accent mark, standard stress rules would make you expect a different pronunciation, so the accent is necessary.