Breakdown of Ayer completamos el proyecto de la escuela.
de
from / of
la escuela
school
el proyecto
the project
ayer
yesterday
Questions & Answers about Ayer completamos el proyecto de la escuela.
Wait, isn't completamos the present tense for 'we complete'? Why is it used here for the past?
For regular -ar verbs, the nosotros (we) form is exactly the same in both the present tense and the preterite (completed past) tense. You have to look at context clues, like the word ayer (yesterday), to know that the action already happened.
Why is the phrasing el proyecto de la escuela instead of just el escuela proyecto?
In English, we often stack nouns together, using the first one like an adjective (like 'school' in 'school project'). Spanish doesn't do this. Instead, you use the preposition de (of) to link them, literally saying 'the project of the school'.
Could I say Ayer nosotros completamos... to make it clearer?
You could, but it isn't necessary. The verb ending -amos already tells us that 'we' did the action. Adding nosotros sounds a bit repetitive here unless you specifically want to emphasize that we finished it, rather than someone else.
What are the other past tense endings for this verb?