Back on and Left off

Hello UsingEnglish.com,

I been looking up for two words that I don't haven't listed in my books. The first one is back on. I heard a sentence like "Is your credit back on", first of all, what does it mean? and for what other examples can I used it?, can you give me an example?. The word is a reduction form of "Back on track" or "Back on your feet"

The second word is left off, I heard sentences like "When we left off in the last class/relationship" and the same question, what does it mean?, for what other examples can I use it?, can you give me an example?.

Thanks in advanced,
Antonio.

[Tdol]

Back on = restored
Left off = finished

Can anyone help me out to make a sentence using the phrasal verb left off. I have one

"Could you please tell me, where we left off" (I wanna add in this sentence, in the last class) How can I do that?

I heard that this phrasal verb can be also used in a relationship, business or a proyect too, can you make a sentence of each one to get the whole picture?

Thanks in advance,
Antonio.

[Tdol]

Could you please tell me where we left off at the end of the last class?

I'm not sure about how you'd use this with a relationship, but with any work, you can stop at some stage and come back later:
Because of the mergency we had to leave off finalising the financial details, etc.

Can I say following the same meaning "I'm so sorry that you left off" In this context left off means to finish or end, right?

Thanks in advance,
Antonio.

[Tdol]

You'd have to say 'left something off', and it would have to be something that wasn't finished, like when they leave off a story in the news because a really big story comes through.