214. The suffix -ig- is used to form verbs indicating the causing, rendering or bringing about of that which is expressed in the root or formation to which it is attached. Verbs containing the suffix -ig- are called causative verbs and are always transitive (22).
a. Causative verbs from adjectival roots indicate that the quality or condition expressed in the root is produced in the object of the verb:
dolĉigi, to sweeten, to assuage (from dolĉa, sweet).
moligi, to soften (from mola, soft).
plilongigi, to lengthen, to make longer (from pli longa, longer).
faciligi, to facilitate (from facila, easy).
beligi, to beautify (from bela, beautiful).
The meaning often resembles that of the predicate nominative (210), as:
Li faris la mondon ĝoja, he made the world glad.
Li ĝojigis la mondon, he gladdened the world.
b. Causative verbs from verbal roots indicate that the action expressed in the root is made to take place:
dormigi, to put to sleep (from dormi, to sleep).
konigi, to make acquainted with (from koni, to know).
mirigi, to astonish (from miri, to wonder).
mortigi, to kill (from morti, to die).
c. Causative verbs may be formed from noun-roots, prepositions, adverbs, prefixes and suffixes whose meaning permits:
amasigi, to amass, to heap up (from amaso, pile).
kunigi, to unite, to bring together (from kun, with).
forigi, to do away with (from for, away).
ebligi, to render possible (-ebl-, 161).
EMPHASIS BY MEANS OF JA.