1. He delayed leaving for Paris.
2. He delayed to leave for Paris.
(Which one is right?)
3. He refused to go / going back home.
4. He rejected to go / going back home.
(Do we have to use 'to go' or' going' in #3 and #4?)
#1 is correct.
In #3 and #4 you could u se either.
Sra is correct for 3 and 4 -- both are grammatically correct.
I think, however, that we use "to go" in that construction far more than "going."