Breakdown of ¿Hace mucho tiempo que ustedes observan el universo?
ustedes
you (plural)
mucho
many / a lot
el tiempo
time
que
that / than
Questions & Answers about ¿Hace mucho tiempo que ustedes observan el universo?
Why is observan in the present tense if the English translation says "have you been observing"?
In Spanish, when an action started in the past and is still happening now, we use the present tense. The formula hace + [time] + que + [present tense verb] tells us the action is ongoing. So, hace mucho tiempo que ustedes observan translates nicely to "you have been observing for a long time," even though observan literally just means "you observe."
Could I just say hace mucho que instead of hace mucho tiempo que?
Why does ustedes come right after que? Can I leave it out?
In this structure, the subject (ustedes) usually goes right before its verb (observan). You can absolutely leave it out and just say ¿Hace mucho tiempo que observan el universo? The -an ending on the verb already tells us the subject is "they" or "you all", so if who you are talking to is already clear, ustedes isn't strictly necessary.
Can I ask this question without putting hace at the very beginning?