Transistor not fully turning off.

While we all twiddle our thumbs waiting for this maybe mythical schematic:-

I just can't remember what happens to the base-emitter current in reverse polarity.

If you swap the collector and emitter round on a transistor it will still work but with a much reduced gain.

but I would not need a schematic for this.

And how many times do you screw it up? I always draw out something that involves three components or more.