verb
BAD : I think it all relies on whether you like being on your own.
GOOD : I think it all depends on whether you like being on your own.
BAD : A country's strength relies on unity.
GOOD : A country's strength depends on unity.
◆◆◆
When you mean that one thing is decided or shaped by another thing, use depend on (NOT rely on ): 'The cost of the trip depends on how long you go for and where you stay.'
Compare: 'Since his wife died, he has had nobody that he could really depend/ rely on.'