To hope is to want something that is possible and likely to happen; to wish is to want something that is impossible or unlikely. Wish is used with past tenses when talking about what is unlikely or impossible. So, if you're inviting a girl to your party, you should say, "I hope you can come." But, if she tells you she will be out of the country at that time, so it's impossible to come, you can show you're disappointed by saying, "I wish you could come." We never say "I wish you can come."
hope 是希望某件事有可能且很可能發生,wish 則是指事情不太可能發生,而且是與過去式一 起連用。所以,如果你邀請一個女生來參加你的派對,你應該說 I hope you can come(我希 望妳能來)。但如果她說那時她要出國不可能參加,你就可以用很失望的語氣對她說 I wish you could come(我真希望妳能來),而不會說 I wish you can come。