These are non-productive derivational affixes for verbs. The rules are loosely defined.

• -wer/er: indicates a result: klef- (to go), klefer- (to arrive); wejo- (to say), wejower- (to inform).
• na-: indicates something that happens before: mocok- (to exist), namocok- (to happen)
• -mu-/-um-: makes something longer or more intensive: nelluz- (observe), nellumuz- (investigate); yano- (hold), yanumo- (squeeze)
• -ra-/-ar-: effect against: yano- (hold), yanaro- (hold back, contain)