Hi Lilith! Great question :D They are all QUITE similar! Quite a lot: "I still have quite a lot of work to do." Quite a few: "I still have quite a few assignments to do." Quite a bit: "I still have quite a bit of work to do." Quite a few is used when talking about countable items (assignments, books, people etc). The other two are used to talk about non-countable items (work, stress, anxiety etc). I would love to hear some more of your questions!

"Quite a lot" can be used with either countable or uncountable nouns. "Quite a few" can only be used with countable nouns, and "quite a bit" can only be used with uncountable nouns.