Proponen ascenderla y acordamos hacerlo.

Spanish often leaves subject pronouns unstated when the verb ending already shows the subject.

• proponen = they propose / you all propose
  In most Latin American contexts, this will usually be understood as they propose.
• acordamos = we agree (or sometimes we agreed, depending on context)

So the sentence has two different implied subjects:

• ellos/ellas/ustedes for proponen
• nosotros/nosotras for acordamos

Spanish does this all the time, so not saying ellos or nosotros is completely normal.

Because object pronouns can attach to an infinitive in Spanish.

Here, ascender is an infinitive, and la is a direct object pronoun attached to it:

• ascenderla = to promote her

With infinitives, Spanish normally puts the pronoun at the end as one word:

• verlo = to see it/him
• hacerla = to do it
• ascenderla = to promote her

You generally would not say la ascender in standard Spanish.

La is a direct object pronoun. It means:

• her, if referring to a woman
• sometimes it, if referring to a feminine noun

In this sentence, it most naturally means her:

• ascenderla = to promote her

So la is the person receiving the action of ascender.

In hacerlo, the lo refers not to a masculine noun, but to the idea or action mentioned before.

So:

• hacerlo = to do that / to do it

In this sentence, lo stands for the action ascenderla:

• Proponen ascenderla y acordamos hacerlo.
• They propose promoting her, and we agree to do so.

This is a very common use of lo in Spanish: it can refer to a whole action, idea, or statement.

Because lo is not referring to her. It is referring to the action of promoting her.

Compare:

• ascenderla → la = her
• hacerlo → lo = that action / that idea

So even though her is feminine, the pronoun in hacerlo is lo because it stands for something like:

• eso
• el hecho de ascenderla
• the act of promoting her

That is why lo is correct here.

It can be either one, depending on context.

For regular -ar verbs, the present and preterite forms for nosotros are often identical:

• acordamos = we agree
• acordamos = we agreed

So only context tells you which one is intended.

In your sentence, without more context, it is often understood as we agree, but we agreed is also grammatically possible.

Here, acordar means to agree or to decide.

Common patterns include:

• acordar + infinitive = to agree to do something
• acordar algo = to agree on something

So:

• acordamos hacerlo = we agree to do it / we agreed to do it

You may also see acordarse de, which means to remember:

• me acuerdo de ella = I remember her

So:

• acordar = to agree
• acordarse de = to remember

They are related forms, but they do not mean the same thing.

In Spanish, ascender can mean to move up, to rise, or to promote someone to a higher position.

So in a work context:

• ascender a alguien = to promote someone

That is why ascenderla works here as to promote her.

This verb may feel more like ascend to an English speaker, but in Spanish it is a normal way to express professional promotion.

Yes, Spanish can express a similar idea in other ways, though the meaning and structure shift a little.

For example:

• Proponen que la asciendan.
  = They propose that she be promoted / that they promote her.

That version uses a subordinate clause with que instead of an infinitive.

Your original sentence:

• Proponen ascenderla
• literally has the sense of They propose promoting her

So both are possible in Spanish, but the infinitive version is more compact.

Because Spanish is a pro-drop language, meaning it often omits subject pronouns when the verb ending already makes the subject clear.

So instead of saying:

• Ellos proponen...
• Nosotros acordamos...

Spanish naturally says:

• Proponen...
• Acordamos...

Adding the subject pronouns is possible, but it usually adds emphasis, contrast, or clarity.

Both are possible, but do so is often the smoother translation in this sentence.

• acordamos hacerlo = we agree to do it
• acordamos hacerlo = we agree to do so

Why do so often sounds better:

Because lo is referring to the previously mentioned action, not a concrete object. English often uses do so in that kind of situation.

So:

• They propose promoting her, and we agree to do so.

is often the most natural translation.

The given word order is completely natural:

• Proponen ascenderla y acordamos hacerlo.

Spanish generally keeps a straightforward order here:

• verb
• infinitive with attached pronoun
• conjunction
• verb
• infinitive with attached pronoun

You could sometimes rearrange things for emphasis, but the original version is neutral and idiomatic.

Yes.

Proponen can correspond to either:

• ellos/ellas proponen = they propose
• ustedes proponen = you all propose

In most Latin American Spanish, ustedes is the normal plural you, so the form is the same.

Without context, the sentence could technically mean:

• You all propose promoting her, and we agree to do so.

But if no one has already established that the speaker is addressing a group, learners usually interpret it as they propose.