dis- denotes Separation: ĵeti, to throw, disĵeti, to scatter, throw about; peli, to drive along, dispeli, to dispel, fali, to fall, disfali, to fall apart, fall to pieces.
ek- denotes a Beginning of an Action, a Momentary Action: iri, to go, ekiri, to begin to go, to start; brili, to shine, ekbrili, to begin to shine, to flash.
ge- denotes the Two Sexes Taken Together: patro, father, gepatroj, father and mother, parents; frato, brother, gefratoj, brother(s) and sister(s); Gesinjoroj B., Mr. and Mrs. B.
mal- denotes the Opposite of an Idea: bona, good, malbona, bad; ŝati, to like, malŝati, to dislike; amiko, friend, malamiko, enemy; laŭta, loud, mallaŭte, softly.—Malo, an opposite; male, on the contrary.
pra- is a prefix of Relationship, corresponding to the English FORE-, GREAT-: patro, father, prapatro, forefather, ancestor; avo, grandfather; praavo, great-grandfather; nepo, grandson, pranepo, great-grandson.
re- denotes Return and Repetition: iri, to go, reiri, to go back, or to go again; repreni, to take back; revidi, to see again.—Ree, again.
Suffixes.
-aĉ denotes that a word is used in a Bad Sense, with Disparagement: domo, a house, domaĉo, a hovel; ridi, to laugh, ridaĉi, to sneer.
-ad denotes Continuation or Duration of an action: paroli, to speak, paroladi, to make a speech; kanto, a song, kantado, singing; vojaĝo, a voyage, vojaĝado, travelling; rido, a laugh, ridado, laughter.
-aĵ denotes some Concrete Thing characterized by the idea contained in the root: bela, beautiful, belaĵo, a beautiful thing; nutri, to feed, nourish, nutraĵo (or nutrantaĵo), food; ĝentila, polite, ĝentilaĵo, a polite act, act of politeness; bovo, ox, bovaĵo, beef.—Aĵo, a thing.