What is the formal way to say a bit in an essay, for example, in the sentence beginning “It is a bit different from”?
Is a little formal enough?
RegDwight recommends Slightly, which is probably the best one-word choice here:
adjective, slight·er, slight·est.
1. small in amount, degree, etc.: a slight increase; a slight odor.
However, if you want to sound more formal, you could use:
marginal (ˈmɑːdʒɪn ə l)
- not considered central or important; insignificant, minor, small
Since writers may use "a bit" to refer to changes ranging from "a tiny bit" (that is, "almost not at all") to "a fair bit" (that is, "significantly but not 'a lot'"), you have to select the most suitable word from a continuum of synonyms that range in magnitude from minuscule to substantial. Here is one possible range of words that you might use to replace "a bit," from least to most in magnitude:
insignificantly, imperceptibly, negligibly, nominally, minimally, scarcely, marginally, slightly, perceptibly, detectably, measurably, discernibly, modestly, meaningfully, incrementally, significantly
Since words, unlike numbers, aren't periodic and equidistant, they don't fall easily along a continuum; and reasonable minds will surely disagree about what falls where—and whether, for example, "quite a bit" belongs in the "a bit" portion of the continuum or in the "a lot" portion. But at least the example range above may give you an idea of how many choices you have in describing a small change in relatively formal words.
If you are quoting differing versions of text, the formal term is variorum