So, I am trying to establish the difference between these words and when you would use one over the other. Here are a few things that I have established so far:
only 以前 can be used with a period of time (e.g. 一个星期以前)
they can all be used colloquially, but 曾经 sounds more formal than 以前
And that is about as far as I have got...
I suppose my main question is when to use 从前 and when to use 曾经 Any insight is greatly appreciated!