語法要點
易錯語法點，配例句講清什麼時候用哪個。
共 24 條
共 24 條
主謂一致：就近原則Either you or he is right. —— 由 either...or、neither...nor、not only...but also 連接的主語，謂語與**最近的那個**保持一致。上例離動詞最近的是 he，所以用 is。語法要點現在完成時 vs 一般過去時I have lived here for 5 years. / I lived there in 2010. —— 現在完成時強調「與現在有關」，常配 for / since / already / yet / ever；一般過去時強調「過去某個時間點結束」，必須配明確過去時間（in 2010、yesterday）。兩者不能和具體過去時間連用完成時。語法要點定語從句：that 與 whichThe book that/which I bought is good. —— 限制性定語從句中 that 和 which 多數可換；但先行詞被 all、only、序數詞、最高級修飾，或先行詞為不定代詞時，通常只用 that。介詞提前時只能用 which（in which）。語法要點虛擬語氣：if 條件句If I were you, I would take it. —— 與現在事實相反：if + 過去式（be 用 were），主句 would + 動詞原形。與過去相反：if + had done，主句 would have done。與將來相反：if + were to do / should do。語法要點非謂語：doing 與 to doI enjoy reading. / I want to go. —— enjoy、finish、avoid、mind、practise、suggest 等後接 doing；want、hope、decide、plan、agree、refuse 等後接 to do。remember / forget / stop 接兩者意思不同：remember doing（記得做過）/ remember to do（記得去做）。語法要點倒裝：否定詞提前Never have I seen such a thing. —— 否定副詞置於句首（never、hardly、seldom、not only、no sooner）時，主句要用部分倒裝：把助動詞提到主語前。no sooner...than 與 hardly...when 是固定搭配。語法要點比較級：as ... as 與 thanHe is as tall as I am. / He is taller than I am. —— as...as 中間用原級，否定可用 not so...as；比較級用在 than 前。比較對象要對等：不能說 His English is better than me，應為 better than mine。語法要點情態動詞表推測It must be true. / It can't be true. —— must 表肯定推測（一定），can't 表否定推測（不可能），may / might / could 表可能。對過去的推測用 must have done / can't have done。注意 mustn't 表「禁止」而不是「不可能」。語法要點被動語態的基本結構The letter was written by Tom. —— be + 過去分詞，時態體現在 be 上。帶雙賓語的動詞可有兩種被動（He was given a book / A book was given to him）。含情態動詞時：must be done。語法要點there be 句型的時態There is / There was / There will be —— there be 的 be 隨後面的名詞單複數和時態變化。就近原則：There is a book and two pens.（離 be 最近的是單數，用 is）。語法要點a number of 與 the number ofA number of students are here. / The number of students is small. —— a number of = 許多（後接複數，謂語用複數）；the number of = ……的數量（謂語用單數）。這是高考與四六級高頻考點。語法要點so ... that 與 such ... thatHe is so kind that everyone likes him. / He is such a kind man that everyone likes him. —— so 修飾形容詞或副詞；such 修飾名詞短語。名詞前有 many / much / few / little 時用 so（so many books）。語法要點it 作形式主語It is important to learn English. —— 真正的主語（不定式、動名詞或從句）後置，用 it 佔位。也可作形式賓語：I find it hard to concentrate。語法要點獨立主格The work finished, we went home. —— 分詞的邏輯主語與主句主語不一致時，自帶一個主語，構成獨立主格。表示時間、原因、條件或伴隨，常見於書面語。語法要點only 引導狀語置句首要倒裝Only then did he realize the truth. —— only + 狀語（then、in this way、after...）置於句首時，主句部分倒裝。但 only 修飾主語時不倒裝：Only he knows the answer。語法要點將來時的幾種表達will / be going to / be about to / be to —— will 表單純將來或臨時決定；be going to 表計劃或已有跡象；be about to 表馬上；be to 表按安排或命令。語法要點引導詞 whether 與 ifI wonder whether/if he will come. —— 賓語從句中兩者常可換；但介詞後、句首主語從句、與 or not 直接連用時只用 whether（whether or not）。語法要點分數的表達與主謂一致Two thirds of the students are here. —— 分子用基數詞、分母用序數詞，分子大於 1 時分母加 s（two thirds）。謂語由 of 後面的名詞決定。語法要點used to / be used to / be used forI used to swim. / I am used to swimming. / It is used for cutting. —— used to do = 過去常常（現在不做了）；be used to doing = 習慣於；be used to do = 被用來做。三個結構意思完全不同，是高頻易錯點。語法要點強調句 It is ... that ...It was Tom that broke the window. —— 結構為 It is/was + 被強調部分 + that/who + 其餘部分。判斷方法：去掉 It is 和 that，句子仍完整，就是強調句；否則是定語從句。語法要點形容詞作定語的位置a beautiful red Chinese silk dress —— 多個形容詞並列修飾名詞時，通常順序為：限定詞 → 評價 → 大小 → 形狀 → 年齡 → 顏色 → 國籍 → 材料 → 用途 → 名詞。語法要點關係副詞 where / when / whythe house where I grew up —— 先行詞是地點用 where、時間用 when、reason 用 why，它們在從句中作狀語；若從句缺主語或賓語，則要用 which / that。語法要點must 與 have to 的區別I must go. / I have to go. —— must 偏主觀（自己覺得必須），have to 偏客觀（外部條件要求），否定形式意思差別很大：mustn't 是禁止，don't have to 是不必。語法要點現在分詞的完成式 having doneHaving finished his work, he left. —— 強調分詞動作發生在主句動作之前，常見於書面語。被動形式為 having been done。語法要點