英語四級改錯題常考要點之非謂語動詞
備考英語四級的過程中，語法是大家認爲最難的地方。下面是小編給大家分享的關於英語四級常考的語法要點，大家可以作爲學習參考。
非謂語動詞
(一) 分詞
現在分詞和過去分詞的區別
①、用於句首作狀語，現在分詞表示主動，過去分詞表示被動
例：Won its war for independence in 1783, the United States then struggled to establish its owneconomic and financial system.
分析：分詞作狀語，主要看是主動還是被動，美國贏得應該是主動,所以改won爲winning
②、用於名詞後面作後置定語，現在分詞表示主動，過去分詞表示被動
例：In the nineteenth century the Mohave Indians lived in the Northern Hemisphere grew their crops on river bottom lands.
分析：生活在什麼地方的人，人生活是主動，因此改爲living
一些動詞後面必須用doing
對於加doing的詞來說，考試中一般出現一個，下面這些詞都是要加doing的，請考生牢記。
mind, finish, enjoy, celebrate, adjust ,advocate, suggest,delay, quit,forgive(原諒)，tolerate，avoid, escape(逃避),spend+名詞+doing;
have trouble/difficult/a problem/ +doing
例：Long before the dawn of recorded history, humans celebrated to harvest their crops.
分析： harvest應改爲harvesting。及物動詞celebrate直接帶名詞、名詞短語或動名詞短語作賓語，故將to harvest改爲harvesting。
例：Some experts have advocated to bring that country into the talks, to revive the intermittent dialogue that began after the 1967 Middle East War.
分析：advocate 後面直接跟doing, 改爲advocate bringing
(二) 不定式
A. 動詞不定式的省略
①、help後面可以省略to
help to do
help sb. to do
例：A good exercise program helps teach people to avoid the habits that might shorten the lives.
分析：the應改爲their. 定冠詞在句中不如代詞所有格明確，如果lives後面有定語就可以用the。
②、使役動詞後面要省略to, 這樣的動詞只有三個
make, let,have sb. do sth
注意get不是使役動詞，get sb. to do sth.
例：A conductor used signals and gestures to let the musicians to know when to play various parts of a composition.
分析：let是使役動詞，後面不需要to, to know改爲know
③、感官動詞
hear, feel, watch, see, notice, observe ,see sb do sth. 強調過程
see sb doing sth 正在做某事
B. 動詞不定式的固定用法
(1)表示第一人
the first woman to do sth.
(2)表示迫使的動詞
一般考三個， allow/ enable/ call, +sb. + to do
例：Besides providing clues to the nature of atoms, mineral analysis allows to speculate geologists about the ancient Earth
分析：allow...to do是固定短語,allow的賓語應在不定式之前,即把改爲: allow geologists to speculate。
(3)表示傾向…的形容詞
be more likely to do 更有可能作某事
be inclined to do傾向於做某事
be liable to do 易於…的
be apt to do
(4)表示目的的名詞，一共有7個這樣的詞，這一條也是最重要的。
固定的句式：
the purpose , the purpose of sth is to do sth.
the objective 目標
aim
goal
reason理由
function功能
intension意圖
例：The function of Louis Sullivan's architecture was providing large uninterrupted floor areas and to allow ample light into the interior.
分析：the function to provide,
例：The chief goal of biochemistry is for understanding the structure and behavior of the carbon-containing compounds that make up various components of a living cell.
分析：the chief goal is to understand
(5) 其他同根名詞
ability to do 受到be able to 的影響
attempt to do 企圖
decision to do 決定, 受decide的影響
ambition,
be ambitious to do
effort
例：For ancient people, myths were often attempts explanation
