'ig'—denotes causing to be in a certain state or condition:

morti, to die, mort'ig'i, to kill (to cause to die).
pura, clean, pur'ig'i, to clean (to make clean).

'iĝ'—denotes to become, to be made to:

ruĝa, red, ruĝ'iĝ'i, to become red (to blush).
riĉa, rich, riĉ'iĝ'i, to become (or to grow) rich.

'il'—denotes an instrument or tool:

kombi, to comb, komb'il'o, a comb.
razi, to shave, raz'il'o, a razor.

'in'—denotes feminines:

frato, brother, frat'in'o, sister.
leono, lion, leon'in'o, lioness.

'ind'—denotes worthiness, to be "worthy of," "deserving of":

laŭdi, to praise, laŭd'ind'a, praiseworthy, worthy of praise.
estimi, to esteem, estim'ind'a, estimable, worthy of esteem.