it 在英語中的意思較多，用法較廣，現總結如下。 一、it作句子的真正主語 1it 指前面已經提到過的人或事物，有時指心目中的或成為問題的人或事物，作真正主語。 例如： Whats this? It is a sheep? 這是什么？這是一只綿羊。 Who is it? Its me (I). 誰？是我。 Its the wind shaking the window. 是風刮得窗戶響。 2it指時間、季節。一般用在無人稱動詞的主語。 例如： What time is it? Its nine. 幾點了？九點了。 Its time for the meeting. Lets go. 開會的時間到了，我們走吧。 What day is today? Its Saturday. 今天星期幾？今天星期六。 Whats the date today? It is October 1st. 今天是幾號？ ？今天是十月一日。 What season is it? It is summer. 現在是什么季節？是夏季。 3it 指氣候。一般作無人稱動詞的主語。 例如： Is it cold in this room? No, it isnt. 屋里冷嗎？不冷。 Whats the weather like today? It is fine. 今天天氣怎么樣？是晴天。 It often rains in summer and it often snows in winter in this city. 這個城市夏天經常下雨，冬天經常下雪。 4it指距離、情況等。一般用作無人稱動詞的主語。 例如： It is five kilometers from my home to the school. 從我家到學校有五公里。 It is very near from this factory to that one. 從這個工廠到那個工廠非常近。 It is a long way to the sea. 離海很遠。Is it well with you? 你身體好嗎？ 二、it作形式主語 動詞不定式、動名詞短語起、從句在句子中起主語作用，而這一部分用詞較多時，可以用it作為形式主語，放在句首代表其后所說的事實上的、真正的主語，而把真正的主語放在后面。 1It +謂語動詞不定式。It 作形式主語，動詞不定式作真正的主語。 例如： It is difficult to climb a mountain. 爬山是很艱難的。 Its a good habit to do morning exercises. 作早操是個好習慣。 Its important to do proper memory work in the study of a foreign language. 在學習外語時適當地做一些有助于記憶的練習是很重要的。 It is right to do so. 這樣做是對的。 2It謂語動名詞短語。It 作形式主語，動名詞短語作真正的主語。 例如： It is dangerous playing with fire. 玩火是危險的。 It is no use learning without thinking. 學而不思則罔。 Its useless arguing with a silly boy. 和笨孩子爭論是沒有用的。 3It 謂語名詞性從句。It 作形式主語，以that 引導的名詞性從句是真正的主語。 例如： It is a pity that you didnt see such a good film. 你沒看這么好的電影，真可惜。 It is certain that we shall succeed. 我們一定會成功。 It is strange that nobody knows where he lives. 真奇怪，誰也不知道他住在哪里。 （It is strange that后面可用虛擬語氣。 如：It is strange that he should have made such a mistake. 他居然犯了這樣一個錯誤，真奇怪。 It is strange that nobody should know where he lives. 居然沒有人知道他住在哪里，真奇怪。） It is said that the plane will take off at ten tomorrow morning. 據說飛機明天上午十點起飛。 三、it作形式賓語 it 作形式賓語，代表其后所說的真正的賓語。真正的賓語是以that 引導的名詞性從句或不定式短語。例如： I consider it wrong that you Chinese students learn English without comparing it with your own language. 我認為你們中國學生學習英語，不和你們自己的語言比較是不對的。 I find it not so difficult to learn a foreign language. 我發現學習一門外語不那么困難。 I remember I made it clear to you that I was not coming. 我記得向你明確表示過我不來。 They want to make it clear to the public that they are doing an important and necessary job. 他們要向公眾表明，他們在做一件重要而又必要的工作。 四、it 用于強調結構 在表示強調的結構中，it 可用作先行代詞，這種結構的句型如下：It +is/was +被強調的部分that +其他部分。如果強調的部分是人，可用who, whom 代替that. 例如： Professor Wang teaches us English every Monday afternoon. 王教授每星期一下午教我們英語。強調主語：It is Professor Wang who teaches us English every Monday afternoon. 強調間接賓語：It is us whom Prof. Wang teaches English every Monday afternoon. 強調直接賓語：It is English that Prof. Wang teaches us every Monday afternoon. 強調狀語：It is every Monday afternoon that Prof. Wang teaches us English. It was here that I first met him. 這就是我初次與他見面的地方。 （強調狀語） It is the people who are realy powerful. 翻譯練習 1)該上課了，快。 It is time for class. Hurry up. 2)從這兒到你們學校遠嗎？不遠，大約一公里。 Is it far from here to your school? ？No, it isnt. Its about a kilometer. 3)從我家到頤和園去很近。 It is very near from my home to the Summer Palace. 4)（天）正在下雨。 Its raining now. 5)電燈是愛迪生發明的。 It was Edison who invented the electric light. 6)我認為學習一門外語是很重要的。 I think it important to learn a foreign language. 7)他通常一天讀兩次英語。 He made it a rule to read English twice a day. 8)從我家去天安門廣場坐公共汽車大約要一個小時。 It takes about an hour to go from my home to the Tiananmen Square by bus. 反意疑問句 反意疑問句相當于“對不對？”“好不好？”“行不行？”，用yes或 no 回答。由兩部分組成，前一部分是陳述句，后一部分是附加疑問短語，中間用逗號隔開，所以反意疑問句又叫附加疑問句。通常的形式是：肯定的陳述句否定的附加疑問，或否定的陳述句肯定的附加疑問。 如： He studies English, doesnt he? He doesnt study English, does he? They are from America, arent they? They are not from America, are they? 反意疑問句的主要形式： 1如果主句是be或其他助動詞（如can, shall, will 等），其反意疑問句用同一助動詞。 如： We are late, arent we? You havent met my wife, have you? He can drive a car, cant he? They used to have difficulty in just making ends meet, didnt (usednt) they? Youd better eat with knives and forks, hadnt you? 2如果主語帶有seldom, hardly, never, rarely, few, little等否定詞或半否定詞時，因為主句本身具有否定意義，附加疑問部分的動詞用肯定式， 如： We seldom go to the cinema, do we? Sue almost never worked, did she?3如果主句部分是 “I am”結構，由于”am not” 沒有相應的縮略形式，附加疑問部分一般用arent I 代替。 如： I am your friend, arent I? Im late, arent I? I am a student, arent I? 在祈使句中的附加疑問部分一般用will you, wont you. 4. 在祈使句中的附加疑問部分一般用will you, wont you. 如： Sit down, will you? Have some tea, wont you? Open the window, wont you? 這種句子可以理解為: Will you do something? 如:Will you open the window? 注意：否定的祈使句之后，只能用will. 如： Dont forget, will you? Dont make so much noise, will you? 5以Lets 開頭的祈使句，肯定的用shall we? 否定的用all right? 或OK?, 如： Lets go back to our seats, shall we? Lets not have hot food this time, OK? (all right?) 這種句子可以理解為：Shall we (do something?), 如:Shall we go back to our seats.這樣有助于理解和記憶。 注意：Lets 與Let us 的區別：Lets包括聽話人在內，應用shall we, 而Let us 不包括聽話人在內，表示“請你讓我們”，要用will you. 如： Lets watch the news on TV, shall we? （表示建議） Let us watch the news on TV, will you? （表示請求） 6主句是I suppose, I think, I believe等時，附加疑問部分則往往與that 從句中的主語和謂語動詞保持對應關系，但要注意否定的轉移。 如： I suppose that you know the meaning of the word, dont you? （這句話明顯是要問“你是不是知道？”而不是問“我是不是這樣認為？”） I dont think that you have read the book, have you? 7當主句的動詞have 表示“擁有”時，附加疑問既可用have, 也可用do, 如： You have a color TV set, havent you/dont you? 當主句的have不表示“擁有”而表示其他意思時，附加疑問要用do, 如： You had a cold yesterday, didnt you? They dont have coffee with breakfast, do they? 8.There be句型的反意疑問句，用there 作主語。 如： There is something wrong, isnt there? There wont be any trouble, will there? 不會有任何麻煩，是嗎？ 9.陳述部分的主語是everyone, someone, anyone, no one, nobody等不定代詞時，其疑問部分的主語可用he, 也可用they. 如： Everyone knows it, doesnt he/dont they? 英語反意