¡Holi! 
I hope you all are doing great for the time being.
My dear student @JaninaP had this question during a live lesson, and I’d like to share it here.
What is the meaning of “hace” in a sentence like: “No esquío desde hace algunos años”?
To me “desde hace” go together to mean what in English is “since”. The thing is that “desde” can also be translated as “since”.
So here are the differences:
-
desde means “since”… refering that from a specific moment in the past, like a date, a year, a month, a day, ‘when I was a kid’, etc. until now.
—> Aprendo alemán con Chatterbug desde enero.
I learn German with Chatterbug since January.
—> Me gusta ese álbum desde la primera vez que lo escuché.
I like this album since I first listened to it. -
desde hace refers to the quantity of time that has passed since an event, for instance : 1 year, some weeks, some hours or days, long time, etc. which makes “for” a more accurate translation of it. Also the emphasis that it gives to the sentence is the continuity of this action in the present… so it
could be more of an equivalent to the use of the present perfect in English.
—> Somos novios desde hace un mes.
We’ve been a couple for a month. Although the literal translation would be in simple present, the function of the sentence is to express what is expressed in present perfect.
—> Vivimos en esta casa desde hace algunos años.
We’ve lived in this house for some years. -
Also there is not an actual translation of hace (as a preposition, not a verb), but it is an equivalent to using “ago”.
—> Hace una hora - an hour ago.
—> Hace un año - a year ago.
Then, “No esquío desde hace algunos años” would be literally: “I didn’t ski since some years ago.”, but I would say the actual meaning of the sentence is “I haven’t skied for a few years.”
I hope this helps a bit to better understand this topic and would appreciate it if there are some fellow tutors who could shed some light on this.
Hasta la próxima. 