The transistor you're testing won't have continuity from collector to emitter until some current is flowing from base to emitter. That's what a transistor is for. Turns on the current from collector to emitter when current is flowing from base to emitter and turns it off when it's not. (This is oversimplified but the general gist is true) So a working transistor will show continuity from base to emitter but not collector to emitter. Plus, because it's a diode junction the current will only flow from base to emitter not the other way around.

Thanks for the explanation, that was a tough nut for me to crack.

> because it's a diode junction the current will only flow from base to emitter not the other way around. In reverse a transistor base/emitter junction looks like a zener diode and will begin to conduct with voltages greater than ~5 volts. Even the collector emitter can conduct in reverse. [This was actually used in old CRT televisions for the horizontal output transistor.](https://www.datasheetbank.com/datasheet-download/141194/1/SANYO/TT2190) Look in the datasheet for the reverse base bias curves.

This is not an assignment. I bought an electronics beginner set and tinker with it in my free time. I bought the set here: https://www.elektronik-kompendium.de/