Escuchamos el lamento ayer.

Because Spanish often drops subject pronouns when the verb already makes the subject clear.

• escuchamos = we listen / we listened
• So nosotros is usually unnecessary.

You could say Nosotros escuchamos el lamento ayer, but it would normally only be added for emphasis, contrast, or clarity.

For example:

• Nosotros escuchamos el lamento, pero ellos no.
  = We heard the lament, but they didn’t.

It can mean either one, depending on context.

For regular -ar verbs, the 1st person plural present and the 1st person plural preterite have the same form:

• escuchamos = we listen
• escuchamos = we listened

In this sentence, ayer tells you it is past:

• Escuchamos el lamento ayer = We listened to / heard the lament yesterday

So here, escuchamos is understood as the preterite.

Because ayer means yesterday, and that automatically places the action in the past.

Even though escuchamos could theoretically be present or past, ayer removes the ambiguity.

Compare:

• Escuchamos el lamento.
  Could mean we listen to the lament or we listened to the lament, depending on context.

• Escuchamos el lamento ayer.
  Clearly means we listened to / heard the lament yesterday.

Spanish uses articles like el, la, los, and las more often than English does.

Here, el lamento means the lament or the wail/moan/cry, referring to a specific sound or expression.

Without the article, lamento would sound less natural in this sentence unless there were a special stylistic reason.

So:

• el lamento = the lament / the cry / the moan

As a noun, lamento usually means something like:

• lament
• wail
• moan
• cry of sorrow
• expression of grief

The exact English choice depends on context. In many real situations, a native English speaker might translate it more naturally as the wail or the mournful cry rather than the more literal lament.

Also, be careful: lamento can also be a verb form meaning I regret in other contexts:

• Lo lamento = I’m sorry / I regret it

But in el lamento, the article el makes it clear that lamento is a noun here.

Yes, Spanish could also use oír, but escuchar and oír are not exactly the same.

A useful basic distinction is:

• oír = to hear
  often about perceiving sound
• escuchar = to listen
  often with more attention

However, in real Spanish, escuchar can also be used in places where English would naturally say hear, especially when talking about hearing a sound clearly or attentively.

So:

• Escuchamos el lamento ayer = natural
• Oímos el lamento ayer = also possible, with slightly more focus on simply hearing it

Both can work, depending on nuance.

Yes, ayer can move. Spanish word order is more flexible than English word order.

All of these are possible:

• Escuchamos el lamento ayer.
• Ayer escuchamos el lamento.
• El lamento lo escuchamos ayer.
  (more marked, with emphasis)

Putting ayer at the end is completely natural.
Putting it at the beginning often gives a little more emphasis to the time:

• Ayer escuchamos el lamento.
  = Yesterday, we heard the lament.

Because the sentence describes a completed action at a specific time: ayer.

The preterite is used for finished events:

• Escuchamos el lamento ayer.
  = We heard/listened to the lament yesterday.

The imperfect would be different:

• Escuchábamos el lamento...
  = We were listening to the lament / We used to listen to the lament

That would suggest an ongoing, repeated, or background action, not a single completed event.

So with ayer and a simple finished event, the preterite is the normal choice.

Because it follows normal Spanish stress rules, so no written accent is needed.

escuchamos ends in -s, so the stress naturally falls on the second-to-last syllable:

• es-cu-CHA-mos

Since that is the expected stress pattern, no accent mark is written.

The same is true in both:

• present escuchamos
• preterite escuchamos

They are spelled the same.

A simple approximation is:

• ayer ≈ ah-YEHR

The stress is on the second syllable:

• a-YER

In most of Spain, the y sound is pronounced similarly to the y in English yes, though exact pronunciation can vary by region and speaker.

So a learner-friendly pronunciation would be:

• escuchamos = es-koo-CHA-mos
• el lamento = el la-MEN-to
• ayer = a-YER

Yes, that is also very natural.

Both are correct:

• Escuchamos el lamento ayer
• Ayer escuchamos el lamento

The difference is mostly about focus and style:

• Escuchamos el lamento ayer: neutral, with yesterday added at the end
• Ayer escuchamos el lamento: slightly more emphasis on when it happened

Spanish often allows this kind of variation without changing the basic meaning.

It is a correct translation, but depending on context, English might prefer a more natural word such as:

• the wail
• the cry
• the moan
• the mournful lament

Spanish lamento can sound a bit broader or more literary than plain everyday English lament. So while the lament is accurate, the best English wording may depend on what kind of sound or expression is being described.

That is a translation issue rather than a grammar issue, but it is a very common thing for learners to notice.