When used alone, "little", "bit", and "little bit" all mean "small". But if you emphasize "little bit" over "little" or "bit" then you are emphasizing HOW SMALL it is. Example1: "John is a bit sick." Here you're just saying that John is sick, but no so sick. Example 2: "John is a little sick." The same here. Example 3: "John is a little bit sick." Here you are emphasizing how small the sickness is. In this case John isn't as sick as in the first two examples. "The movie was a bit different this time." and "The movie was only a little bit different this time." In the both cases the movie was different, but in the second one it was way less different than in the first one. I hope it makes sense.

A. That sounds a bit strange. (or "rather strange") B. That sounds a little strange. (or "somewhat strange") C. That sounds a little bit strange (same as A, but softened with the use of "little") Americans nowadays prefer to say "kind of strange" Hope the example helps. Greetings! Teacher Charles, https://www.italki.com/teacher/5853252