Daniela teaches Italian in a classroom, complete with blackboard, chalk, eraser, and students. Her lessons are very popular and people love her spontaneity and teaching style. She addresses grammatical topics one by one, geared to both beginning and intermediate level students.
A student asked Daniela to explain the difference between finché and the adverb fino. In fact, these words are tricky for English speakers to grasp. We're talking about "until" and "as long as," and in questions, "how far" and "how long."
In English, the difference between "until" and "as long as" is quite distinct, but in Italian, it's a little blurry because the presence of the negative word non (not) might change the meaning of a phrase or it might not. When the meaning is not altered by its presence, the word, in this case non (not), is "pleonastic." We're talking about finché and finche non.