中考英語語法精講例析 介詞
［誤］ in the beginning of the book, there are some interesting stories.
［正］ at the beginning of the book, there are some interesting stories.
［析］ at the begining與at the end都是指某事物的開始與結束部分，均不指時間范圍，而in the beginning 則是指開始一段時間。in the end＝at last是指"最終，終于"之意。
［誤］ till the end of next week. i will have finished this work.
［正］ by the end of next week. i will have finished this work.
［析］ by 引起的時間狀語表示了動作的截止點，其意思為"不遲于某一時刻將工作做完"，所以主句一般是完成時態。當然可以有將來時態，如：i'll be there by five o'clock.而till則表達其一動作一直持續到某一時刻，但句中的動詞一定要用持續性動詞，而瞬間的截止性動詞應用其否定句式，如：i won't finish this work till(until) next weekend.
［誤］ he came to london before last weekend.
［正］ he had come to london before last weekend.
［正］ he came to london two weeks ago.
［析］ before 一般要與完成時連用，而ago則與一般過去時連用。
［誤］ i have studied english for three years gince i had come here.
［正］ i have studied english for three years since i came here.
［析］ since用來表達主句動作的開始時間，所以其引出的從句中應為過去時，而不能用完成時態
［誤］ i can help you repair this bike. you will get it after two hours.
［正］ i can help you repair this bike. you will get it in two hours.
［析］ 中文經常講兩小時之后來取，兩天內會修好，而這個介詞在英文中要用in而不要用after。其原因有二，①after 多用于過去時，如：i arrived in new york. after three days, i found a job in the bank. ② after 加時間是表達一個不確定的時間范圍，如：after three days, 即三天之后的哪一天都可以。所以在許諾若干時間內會完成某事時，一定要用介詞in。
［誤］ three days after he died.
［正］ after three days he died.
［正］ three days later he died.
［析］ after 與 later都可以用來表達一段時間之后，但它們所處的位置不同，after 在時間詞前，而later在時間詞后。
［誤］ she hid herself after the tree.
［正］ she hid herself behind the tree.
［析］ after多用來表達某動作之后，所以有的語法書中稱它為動態介詞，如：i run after him. after finishing my homework, i went to see a film. 而behind則多用于靜態事物之后。
［誤］ there is a beautiful bird on the tree.
［正］ there is a beautiful bird in the tree.
［析］ 樹上長出的果實，樹葉要用on, 而其他外來的人、物體均要用in the tree.
［誤］ shanghai is on the east of china.
［正］ shanghai is in the east of china.
［析］ 在表達地理位置時有3個介詞：in, on, to。 in表示在某范圍之內; on表示與某地區接壤；to則表示不相接。如：japan is to the east of china.