(2) = 'ever' in pronouns and particles, where it gives an indefinite sense, as in ā-hwǣr (anywhere), ā-wiht (anything).
ǣġ- from ā-ġe-, the ā being mutated and the e dropped, has a similar meaning, as in ǣġ-hwelc (each), ǣġþer = ǣġ-hwæþer (either).
be-, originally 'by,' 'around' (cp. the preposition be), (1) specializes the meaning of a transitive verb, as in be·sęttan (beset, surround), be·sċieran (shear); (2) makes an intransitive verb transitive, as in be·þęnċan (consider) from þęnċan (think); (3) gives a privative meaning, as in be·hēafdian (behead). In some words, such as be·cuman (come), it is practically unmeaning.
for- (which is distinct from the preposition for) generally has the sense of 'loss' or 'destruction,' as in for·dōn (destroy), for·weorþan (perish). Of course, if the verb with which it is compounded already has this meaning, it acts merely as an intensitive, as in for·brēotan (break up, break), for·scrincan (shrink up). It also modifies in a bad sense generally, as in for·sēon (despise), or negatives, as in for·bēodan (forbid).
ġe- originally meant 'together,' as in ġe·fēra (fellow-traveller, companion) from fēran (travel). With verbs it often signifies 'completion,' 'attainment,' and hence 'success,' as in ġe·gān (conquer), originally 'go over,' or 'reach,' ġe·winnan (win) from winnan (fight). Hence generally prefixed to hīeran and sēon, ġe·hīeran and ġe·sēon strictly meaning 'succeed in hearing, seeing.' It is generally prefixed to past participles (p. [23]), where it originally gave the meaning of completion—ġe·lufod = 'completely loved.'
mis- = 'mis,' as in mis-dǣd (misdeed).
n- = ne (not), as in nā (not), literally 'never,' nǣfre (never), næs (was not) = ne wæs.
on- as a verbal prefix has nothing to do with the preposition on. It properly signifies 'separation,' as in on·lūcan (open) from lūcan (lock, close), but is often practically unmeaning, as in on·ġinnan (begin).
or-, literally 'out of,' is privative, as in orsorg (unconcerned) from sorg (sorrow).