人教版英语八年级下册易混辨析：unless和until用法区别(共2页).doc

精选优质文档-倾情为你奉上易混辨析：unless和until用法区别A good storyteller must be able to hold his listeners curiosity _ he reaches the end of the story.A. when B. Unless C. after D. until解析：答案是D。不少同学可能会误选unless，引导条件状语从句，但分析语境可知，该空格表示“直到”，强调时间的延续，应用until引导时间状语从句。本题着重考查unless和until的用法区别，其用法区别是热点考点。本文拟谈一谈unless和until的用法区别。一、作为从属连词含义不同，引导从句性质不同unless与until均为从属连词，unless表“除非”，强调条件，引导条件状语从句；until表“直到”，强调时间的延续，引导时间状语从句。1. I didnt know the news until my teacher told it to me. 2. I couldnt know the news unless my teacher told it to me.3.Was his father very strict with him when he was at school? Yes. He had never praised him until he became one of the top students in his grade. 解析：句1动词didnt know表明该句强调时间的延续，表明“我不知道这消息”的状态一直延续到“老师告诉我”，因此应用until引导时间状语从句。句2动词couldnt know表明该句强调条件，表明“我不可能知道这消息，除非老师告诉我”，因此应用unless引导条件状语从句。句3表明“他爸爸从来没有表扬他”的状态一直延续到“他变成年级最好的学生之一”，因此也应用until引导时间状语从句。二、作为从属连词引导的从句常用一般现在时表示将来unless引导的条件状语从句和until引导的时间状语从句常用一般现在时表示将来。例1：除非邀请你否则别进来。误：Dont come in unless you will be invited to.正：Dont come in unless youre invited to.例2：除非他来，我们不可能去。误：Unless he will come, we wont be able to go.正：Unless he comes, we wont be able to go.三、作为从属连词引导的状语从句可转换为省略式创新句型unless引导条件状语从句和until引导时间状语从句时，如果主从句主语一致(或主从句主语不一致，但从句主语为it)，从句谓语部分含有be，可将从句主语和动词be省略，构成省略式创新句型。例1：I wont come to see you unless I am asked to. 除非你邀请我，我才会来看你。解析：因为主从句主语一致，从句谓语又含有am，所以可将从句主语I和动词am省略，构成省略式创新句型：I wont come to see you unless asked to.例2：The soldiers will not cross the river unless they are ordered to. 除非接到命令，战士们不会过河。解析：因为主从句主语一致，从句谓语又含有are，所以可将从句主语they和动词are省略，构成省略式创新句型：The soldiers will not cross the river unless ordered to.注意：until也可作为介词。例如：I have remembered her until now. 直到现在我还记得她。 专心-专注-专业