"reason of" vs "reason for"

reason for 後面應該跟 him, her, me...，然後組成reason for him to do something
reason of learning Spanish是指 learning spanish的原因

不過，I am going to Spain for learning Spanish 比較好，精簡不累贅
Nobody knew the reason of the delay and Nobody knew the reason for the delay is both acceptable. but i would choose of preferrably.

1) reason of
2) reason of / reason for
of or for is depending on which sentences u r using , sometimes both ok , but sometimes only one is ok......

All are noun phrases used as of reasons:-
(1)for(---)reason of learning , rather than "for."
(2)the reason of(---) delay ,rather than "for."
The Spainish are the people of Spain and their language Spainish are also spoken there.