Revisamos el montón ayer.

Spanish often leaves out subject pronouns because the verb ending already shows who is doing the action.

• revisamos = we check / we checked
• So nosotros revisamos is possible, but nosotros is usually unnecessary unless you want emphasis or contrast.

For example:

• Revisamos el montón ayer. = We checked the pile yesterday.
• Nosotros revisamos el montón ayer, no ellos. = We checked the pile yesterday, not them.

By itself, revisamos can be either:

• present: we check / we review
• preterite (simple past): we checked / we reviewed

This happens with many -ar verbs in the nosotros form.

Here, ayer makes it clear that it is past:

• Revisamos el montón ayer. = We checked/reviewed the pile yesterday.

If there were no time word, the form could be ambiguous.

Because ayer means yesterday, and that time expression refers to a finished point in the past. That naturally pushes revisamos to be understood as the preterite form.

So:

• Revisamos el montón. → could be present or past, depending on context
• Revisamos el montón ayer. → clearly past

Spanish often relies on context and time markers like this.

Revisar is a flexible verb. It often means:

• to check
• to inspect
• to review
• to go through

So depending on context, Revisamos el montón ayer could mean things like:

• We checked the pile yesterday
• We went through the pile yesterday
• We inspected the pile yesterday

It does not always mean review in the academic sense. It can also mean physically checking something.

Montón is a noun, so if you are talking about a specific pile, Spanish normally uses an article:

• el montón = the pile

Spanish uses articles more often than English in some cases, but here it is very straightforward: it refers to a particular pile.

If you said just montón in this sentence, it would sound incomplete.

No. Montón can be:

1. literal: a pile, heap, stack

   • el montón de papeles = the pile of papers

2. informal quantity expression: a lot / loads

   • un montón de gente = a lot of people
   • Me gusta un montón. = I like it a lot.

In Revisamos el montón ayer, with el montón, it most naturally sounds like a specific literal pile unless context suggests otherwise.

Because Spanish word order is fairly flexible, especially with time expressions.

All of these are possible:

• Revisamos el montón ayer.
• Ayer revisamos el montón.

The version with ayer at the end sounds natural and neutral. Putting ayer first can give a little more emphasis to the time.

Yes, absolutely.

Both are correct:

• Revisamos el montón ayer.
• Ayer revisamos el montón.

The difference is mainly emphasis and rhythm:

• Ayer revisamos el montón highlights when
• Revisamos el montón ayer is a very normal neutral order

In Spanish from Spain, ayer normally goes with the preterite:

• Revisamos el montón ayer.

That is because ayer refers to a completed time period that is finished.

Using hemos revisado with ayer is generally not the standard choice in Spain. In standard Spain usage, you would usually say:

• Hoy hemos revisado el montón. = Today we have checked the pile.
• Ayer revisamos el montón. = Yesterday we checked the pile.

So this sentence is a very typical Spain-Spanish choice.

Yes. The infinitive is revisar, which is an -ar verb.

For nosotros, the form is:

• present: revisamos
• preterite: revisamos

That is why this form looks identical in both tenses.

Compare:

• yo reviso
• tú revisas
• él/ella revisa
• nosotros revisamos
• vosotros revisáis
• ellos revisan

And in the preterite:

• yo revisé
• tú revisaste
• él/ella revisó
• nosotros revisamos
• vosotros revisasteis
• ellos revisaron

Not usually in the same way.

• mirar = to look at
• revisar = to check / inspect / go through

So if you mean carefully examining the pile, revisamos is better.

Compare:

• Miramos el montón. = We looked at the pile.
• Revisamos el montón. = We checked / went through the pile.

So revisar suggests more active inspection than mirar.

A simple pronunciation guide:

• revisamos: reh-bee-SAH-mos
• el: ehl
• montón: mon-TON
• ayer: ah-YEHR

A more connected pronunciation would sound roughly like:

reh-bee-SAH-mos ehl mon-TON ah-YEHR

A couple of useful points:

• v in Spanish sounds closer to a soft b
• the stress in montón falls on the last syllable because of the written accent: -tón
• ayer in Spain is usually pronounced with a clear y sound at the start of the second syllable

No. In natural English, that would not work, and in Spanish the word ayer blocks the present-tense reading.

Even though revisamos can technically be a present-tense form in isolation, once you add ayer, the sentence is understood as past:

• Revisamos el montón ayer. = We checked/reviewed the pile yesterday.

So in this full sentence, learners should read revisamos as preterite.