Be-, old form of by: betimes, bypath; in verbs: bedaub (daub all over), bewail (wail for), benumb (make numb).
For-, intensifies the meaning, (thoroughly): forbear, forlorn, forswear, forbid (command against), forego.
Fore-, first, before: foresight, forejudge.
Mis-, wrong, wrongly: misdeed, miscall, mislead.
Un-, not: unholy, unafraid. In verbs, it indicates the reverse of the simple verb: unbind, unfold, unmask.
With-, against, (from): withstand, withers (of a horse), withhold.
Separable Prefixes.
After, after: aftergrowth, aftermath (= after the mowing), afterthought.
All (old Eng. al), all: almost, alone.
Forth, forth: forthcoming.