五.條件狀語從句　　條件狀語從句可分為真實條件句和if引導的非真實條件句?！　) if, unless 引導的條件狀語從句　　unless 意義上相當于if…not。 unless一般不用于非真實條件句。　　I will not lend the book to you unless you can return it in time.　　II) only if和if only引導的條件狀語從句　　only if意為“只要……”，引導真實條件句，若only if放在句首，后面的主句要用倒裝結構。 if only 引導虛擬條件句，也可引導感嘆句，意為“但愿……”、“要是……就好了”?！　nly if you study hard will you pass the final-examination.　　只要你努力學習，就會通過期末考試?！　f only we had arrived at the airport in time, we could have met him.　　要是我們按時趕到車站，我們也許就能見到他?！　f only it would stop raining! 但愿雨能夠停下來!　　六.讓步狀語從句　　I) though, although引導的讓步狀語從句　　這兩個詞同義，但although語氣較重，且多用于句首。though引起的狀語從句可用也可不用倒裝?！　trange though it may seem (Though it may seem strange), he remained single all his life. 他終生未娶，此事似乎令人覺得奇怪。　　II) even if 和even though (即使) 引導的讓步狀語從句　　I was persuaded to do the job, even it / even though I didn’t want to.　　我被說服去做那件工作，即使我并不想做?！　II) as 引導的讓步狀語從句： 必須用倒裝結構——把從句中的表語、狀語或謂語動詞放在句首。 作表語的名詞前如有不定冠詞a (an)，再倒裝結構中，前面不能再加冠詞?！　uch as I admired his courage, I don’t think he acted wisely.　　盡管我欣賞他的勇氣，但我認為他的行為并不明智。　　IV)while引導的讓步狀語從句：意義上相當于although，只能放在句首?！　hile I understand your viewpoint, I don’t agree with you. 雖然……　　V)“whether …or…”, “wh-詞+ ever”結構和“no matter + wh-詞”引導的讓步狀語從句，意為“無論……”。 Whatever后接名詞，however后接形容詞或副詞。　　Whatever (No matter what) may happen, we will not change our mind.　　However often you ring, no one will answer. 無論你打多少次電話，都不會有人接?！　ll matter, whether it is a gas, a liquid or a solid, expands as the temperature rises.