讓步狀語從句:連接讓步狀語從句的連接詞有：although,though,even if,even though,however,whatever,whenever,whoever,whichever.1：when和while引導的時間狀語從句與這一時態(tài)連用.所以區(qū)別when和while的用法成了這一單元的難點.（一）、when,while都有“當……時候”的意思.when既可表示某一點時間,也可以表示某一段時間 .在when引導的時間狀語從句中,其謂語動詞可以是延續(xù)性的,也可以是非延續(xù)性的,可與主句中的謂語動詞同時發(fā)生,也可在其后發(fā)生.例如：1、I was just reading a book when she came into my room.她走進我房間時,我正在看書.2、Were you writing when the teacher came in?老師進來的時候,你在寫信嗎?3、When he was a child he was always trying out new ideas.他小時候就常常試驗一些新的設想.（二）、while只能表示某一段時間,不能表示某一點時間.在while引導的時間狀語從句中,其謂語動詞只能是延續(xù)性的,而且也只能與主句中的謂語動詞同時發(fā)生或存在.例如：1、While Jim was mending his bike,Lin Tao came to see him.正當吉姆修自行車時,林濤來看他.2、You can’t do your homework while you’re watching TV.你不能一邊看電視一邊做家庭作業(yè).（三）、另外,when和while的區(qū)別還在于：while引導的時間狀語從句多用進行時態(tài),而when引導的時間狀語從句多用一般時態(tài).例如：1、While they were talking ,the bell rang.正在他們談話的時候,上課鈴響了.2、I was doing my homework when my mother came back home yesterday evening.昨天晚上媽媽回家的時候,我正在做家庭作 １ Although (though) I gave him some advice,he didn’t take them.２ John continued to work hard even if (even though) he felt sick.３ Whatever you do,I will support you.==No matter what you do,I will support you.４ Whoever you may be,I will not let you in.===No matter who you may be,I will not let you in.５ However difficult it may be,we will overcome it.=== No matter how difficult it may be,we will overcome it.注意：一般情況下,although等于though,even if等于even though,however等于no matter how,wh-ever等于 no matter wh-．