set off vs happen

set off and happen both are verbs.

Word	Noun	Adjective	Verb	Adverb
set off	No	No	Yes	No
happen	No	No	Yes	No

set off (verb)	happen (verb)
cause to burst with a violent release of energy	come to pass
set in motion or cause to begin	come into being; become reality
direct attention to, as if by means of contrast	happen, occur, or be the case in the course of events or by chance
provoke or stir up	come upon, as if by accident; meet with
put in motion or move to act	chance to be or do something, without intention or causation
depart for someplace
make up for