Revisamos el tapón de cerumen antes de que entremos.

to check

Breakdown of Revisamos el tapón de cerumen antes de que entremos.

• entrar: to enter
• antes de que: before
• el tapón de cerumen: the earwax blockage

Questions & Answers about Revisamos el tapón de cerumen antes de que entremos.

Why is it antes de que entremos and not antes de entrar?

Because antes de que is used when a new clause with its own subject follows. Here, the second part has a conjugated verb, entremos, and the subject is understood as we.

• antes de entrar = before entering / before we enter
• antes de que entremos = before we enter

Both can be possible in some contexts, but antes de que + subjunctive is especially common when the speaker wants to present the second action as a separate event.

A useful rule:

• antes de + infinitive → when there is no new finite verb
• antes de que + subjunctive → when there is a new clause

So:

• Antes de entrar, revisamos...
• Revisamos... antes de que entremos.

Both are grammatical, but the structure in your sentence specifically requires que + subjunctive.

Why is entremos in the subjunctive?

Because antes de que normally triggers the subjunctive.

In Spanish, the subjunctive often appears after expressions that refer to something not yet completed, uncertain, expected, or dependent on another action. Entering has not happened yet at the point of checking, so Spanish uses the subjunctive:

• antes de que entremos

This is very similar to other time expressions that trigger the subjunctive when talking about future or pending actions, such as:

• cuando entremos
• hasta que entremos
• en cuanto entremos

So the key point is: antes de que + subjunctive = standard grammar.