1) to make sure (that) something will happen (ensure)
to find out (something)(in order to be certain)
make sure
to state, show, the truth of (opinions, feelings etc)
ratify, validate, prove
to make sure (that) something will happen
guarantee; make secure
to test the truth or accuracy of (a report etc); (of an event etc) to prove, show, the truth of (something)
confirm, validate
pledge, promise
pledge, promise