Breakdown of ¿Puedes calcular la órbita de estas estrellas?
de
from / of
poder
to be able to / can
estas
these (feminine)
la
the (feminine)
Questions & Answers about ¿Puedes calcular la órbita de estas estrellas?
Why is calcular in its base form instead of being conjugated?
When two verbs are used together to express a single idea, only the first verb is conjugated. Here, puedes tells us who is doing the action (you), so the second verb calcular stays in its base form, or infinitive. This is exactly like saying "can calculate" in English.
Why do we use estas instead of estos?
In Spanish, words for "this" and "these" have to match the gender and number of the noun they describe. Because estrellas (stars) is a feminine plural noun, we use the feminine plural word estas. If the noun were masculine, like planetas, we would use estos.
Why does the verb poder become puedes here?
The verb poder (to be able to / can) is a stem-changing verb. In the present tense, the o in the root of the word changes to ue for most forms. That is why it becomes puedes when talking to "you".