prefiex im/ non/ in/ un

zyc50

Usually:

in + ADJ,
e.g. inaccurate, inconsistent, incapable, immature, impolite,
impersonal,
immobile, immortal, immoral

  when the root of the word starts with an M or P, i.e. bilabial
consonants,
'iN' becomes 'iM', in expectation of the following sound.

non - ( Adj), it is added in the front but don't really form a new word,
      e.g. non-flammable, non-toxic, non-compliant

un + Verb,  to REVERSE or UNDO the action of the original verb
      e.g., undo, undress, unfold, uncover, unseal


dis + Verb, to do just the opposite
     e.g. disqualify, discontinue, disembark, disassemble,
disappear,
disagree, disapprove, disbelieve