would could should等在不同时态中的用法

Would,Could多用于委婉语气,尤其在提问时常用.如：Would you Please do me a favor?Should表示责任、建议或劝告,翻译为“应该” 如:You should tell him this.用于虚拟语气时,将来时的虚拟语气只能用should.should的...