Asking for some VERY basic help with "from"

Greetings All,

What’s confusing me is ab, de, and ex. My text tells me the following(sorry, no macrons):
a, ab (prep. with abl.) from, away from
de (prep. with abl) from, down from, about, concerning
e, ex (prep. with abl.) from, out of

What’s confusing me is this: What if I just want to say “from” and not down, away, or out of?
Possible example: “I learn Latin from my teacher.” Which “from” and why?
How best to decide in translation exercises?

As always,
TIA! - Cathexis

Looking in the dictionary helps.

disco

disces tu quidem a principe hujus aetatis philosophorum, et disces quamdiu voles,” Cic. Off. 1, 1, 2:

Just a quick general observation, that prepositions in nearly all langauges can be highly idiomatic, and they are sometimes used in ways we wouldn’t expect from the first English glosses and usages we see, and Latin is no exception. “On the right” ā dextrō, not “in dextro…” You can only learn this by experience in the language and seeing how the prepositions are actually used in context.

Okay,

Sort of like a non-English speaker wondering why English speakers would say, “in the know”
when it might sound like someone saying knowledge is a location you occupy rather than
just an artifact of modern English whatever it’s original etymology might have been.
(My attempt at humor).

Bottom line: “Brush off any frustration and keep pushing forward lowly grasshopper.”

My sincere thanks,
Cathexis