can't help與can'twit

can't help抑制不住，禁不住; 不由; 不由自主; [例句]I'm afraid I can't help you.恐怕我幫不了妳。can't wait迫不及待; 無法等待; 等不及; [例句]I can't wait to marry you.我等不及和妳結婚了。