1. I wish that I were younger. 2 I wish that every person in this world were nice. 3. I wish that I could live forever. As you can see, those wishes are NOT possible. 4. I hope that peace will soon come to country X. 5. I hope that you pass the test next week.' 6. I hope that Ms. X wins the election. As you can see, those hopes ARE possible. ***** There is one exception about "wish." People often say "I wish you a very happy birthday." That is, of course, possible.

Just to add onto James' answer there.... To the effect of what he wrote, note that "wish that" takes a subjunctive verb! (precisely because those wishes aren't possible)