Esperamos la llegada.

We are waiting for the arrival.

Breakdown of Esperamos la llegada.

• esperar: to wait for
• la llegada: the arrival

Questions & Answers about Esperamos la llegada.

Is esperamos present tense here, or could it also be past?

It can be either, depending on context.

• Present indicative: we wait / we are waiting / we expect
• Preterite: we waited / we expected

This happens because for -ar verbs, the nosotros form is the same in the present and the preterite:

• esperamos = present
• esperamos = preterite

So the surrounding context tells you which one it is. On its own, Esperamos la llegada is often understood as present, but it is technically ambiguous.

Why is there no subject pronoun like nosotros?

Spanish often leaves out subject pronouns because the verb ending already tells you who the subject is.

• espero = I wait / expect
• esperas = you wait / expect
• esperamos = we wait / expect

So Esperamos la llegada already means we because of -amos.
You could say Nosotros esperamos la llegada, but that usually adds emphasis or contrast, such as:

• Nosotros esperamos la llegada, pero ellos no.
  We are waiting for the arrival, but they are not.

Why is there no por after esperamos? In English we say wait for.