'94 brake/tail ights partially working

Hi, I don't know a ton about cars but i'm trying to get a possible explanation for why my tail lights are only coming on when in reverse. Sorry i don't know the right terms but the bulbs are all working (apparently) and the reverse lights work, the signals work, the hazards work. The backlights just wont come on by themselves at night anymore. Hope this makes sense. any ideas? or directions?

is this a wiring thing? or a switch? i doubt i'll undertake the solution myself but at least knowing what it could be will keep me from getting overcharged. Thx in advance.

plz let me know if more info is needed.

this is a little confusing, so let me try to understand this better, Your taillights only work when your reverse lights are on? What about your parking lights, do they go on when you turn the lights on at night? Lastly what about the 3rd brake light in the back window, is that going on at all, ( check the bulbs if not)

My guess on all of this, would be to check a fuse first, Second idea that could be the problem is the multifunction switch since they are common to fail in these years g/a's causing the main tailights not to work when pressing the brakes.. but the turn signals and parking lights will still work. It's possible that you have a short somewhere as well, but sometimes they are harder to trace... hopefully this helps out some... good luck and welcome to the forums.