Learn Spanish (Latin America): Agradecería que revisaras el reverso cuidadosamente. - I would appreciate it if you checked the back carefully.

The main verb Agradecería is in the conditional tense. When you make a polite request or express a wish using a verb of emotion or influence in the conditional, it forces the verb in the following que clause into the imperfect subjunctive. Even though the checking hasn't happened yet, this grammar pattern requires the past subjunctive to match the conditional.

Why is there no translation for the word "it" from the English sentence "I would appreciate it"?

In English, we use "it" as a dummy pronoun before "if you checked". Spanish does not use a placeholder pronoun here. The verb agradecer connects directly to the que clause, so trying to add a direct object pronoun like lo before agradecería is unnecessary and unnatural.

Could I use the other imperfect subjunctive ending and say revisases here?

Yes, revisases is grammatically correct and means the exact same thing. However, in Latin America, the forms ending in -ra (like revisaras) are overwhelmingly more common in everyday spoken and written Spanish than the -se forms.

Is el reverso the most common way to say "the back" in everyday conversation?