why "Hace"

Why “hace”

Hace cuánto tiempo que está aquí?

How long have (you) been here?

¡Hola jrsundy y Alme!

Alme has already provided a great explanation on how hace "(it) makes" is used to talk about time; if you're looking for a grammar lesson explaining this topic in full, jrsundy, you'll want to check out Level 2's Lesson 10.5: Since When and For How Long? The first main section (titled "Using 'For' to Talk About Time") is the one you're looking for in order to understand how hace is used with verbs in the present tense.

As for atrás, Alme: it can indeed be used to mean “ago,” much like hace can. Its placement is just a little different, as you've seen (hace diez años vs. diez años atrás “ten years ago”), and atrás is also used more often to set the scene of a story (as opposed to simply giving a length of time). For that reason, it might be more helpful to think of atrás as being closer to “back” or “earlier” in English. 

If either of you still have any questions, please don't hesitate to ask!

Saludos,

Liss

¡Hola Alme!

Yes indeed, durante is another option that can be used to mean “for,” and you could absolutely use it in that sentence instead! It's worth noting, though, that durante tends to be more commonly used to mean “for” in Spain than in most of Latin America.

There is actually a section in Lesson 11.6: POR vs. PARA that gets into the options of using por, durante, or no preposition at all to mean “for” when talking about lengths of time, if you're interested in more options; you can find it under the subheading “4. Duration and Imprecise Times.” 

Saludos,

Liss