"verbs whose conjugations are annoying and confusing to foreigners" (of which Russian has too many to count)
But even though there are tons of these verbs, it's possible to group them into (I'm guessing) fewer than three-dozen categories, such as:

  • "verbs that behave like пасть"
  • "verbs that behave like давать "
  • "verbs that behave like бить"


...and so forth.

Learning two or three dozen basic conjugational patterns seems like a lot, but obviously it's a lot more efficient than memorizing the individual conjugations for thousands of different verbs!

I'm not sure whether there's some kind of "sticky" post somewhere on MR summarizing all the conjugations by pattern -- does anyone know?