1、 it作形式賓語、形式主語 it 作形式賓語一定義 當不定式（短語），動名詞（短語）或從句在句子中作賓語時，為保持平衡，避免句式結構的混亂，常用it 作形式賓語，而將真正的賓語方在句尾。此時it只起引導作用，無意義。adj.n.(for sb) to do sth.從句doing sth2 結構+S + v + it+句型結構為“1236”1指形式賓語it；2指賓語的兩種形式：形容詞和名詞；3指真正的賓語的三種形式：不定式短語，動名詞短語或從句6指主句中常用動詞：think, believe, consider, make, find, feel. find possible1.S+ thin

2、k + it+ necessary +( for sb. ) to do sth. /clause. feel important a rule2. S+ V + it + ones duty + ( for sb. ) to do sth. /clause an honour no good3.S + V + it + + doing sth. no use 三用法當不定式、動名詞、從句等用作賓語且其后跟有賓語補足語時，就應在賓語補足語前使用沒有具體意義的形式賓語，而將真正的賓語移至句末。it作形式賓語,代替不定式、動詞ing短語、從句.其基本結構為“動詞+it+賓語補足語+不定式(動名詞或

3、從句)”：4 例句it作形式賓語,代替不定式、動詞ing短語、從句.1.He found it difficult to stop smoking 2.I think it best that you should do more exercise.3.She thought it no good worrying about him。4. We find it necessary that we practise English daily.5. She made it a duty that she takes care of her sick mother.6. I have made

4、it my habit that I get up before 6:30 everyday .5 鞏固練習（1） They found it difficult（發覺難）to finish their work in two days. （2） We think it our duty（認為是我們的職責) to clean our classroom every day. （3） I dont think it possible to master a foreign language without much memory work. (4) 他認為從現在開始努力學習趕上他人是有可能的.

5、He thinks it possible that he works hard to catch up with others.（5）他發現很難使別人理解他. He found it difficult to make himself understood. 我認為我們保持冷靜很重要. I think it important that we should keep calm.6 it 作形式賓語的特殊用法（1）某些表示“喜、怒、哀、樂”的動詞，如like, enjoy, love, hate, dislike, appreciate等 后往往不能直接接賓語從句；必須先由it擔任形式賓語，指

6、代后面從句所述內容,再接從句(通常是if/when引導).1.We would much appreciate it if you could do us that favour.要是你們能幫我們這個忙，我們將非常感激。2.I'd prefer it if I didn't have to finish the work.要是我不必完成那項工作，那就太好了。3. I would appreciate it if you would turn the music down .4. I hate it when people talk with their mouths full.

7、 （2） 某些含有介詞的動詞短語如 depend on, rely on，answer for, insist on,stick to，look to（注意，指望，照看），count on（指望，依靠），see to（負責，注意，照料）,等結構中往往不能直接接賓語從句；必須先由it擔任形式賓語,再接從句. 1.I'll see to it that everything is ready in time. 我將負責按時做好一切準備。 2.You may depend on it that Tom will help you with your English.(你放心，湯姆會幫助你學英語的。) You may depend on it that they'll support you. 3.Im counting on it that you