1. a

　?。畚螅?I think it is an useful English dictionary.

　　［正］ I think it is a useful English dictionary.

　　［析］ 在不定冠词a与an的用法中要注意的一点是：an用在以元音开头的词之前；而a则用在以辅音开头的词之前。要特别注意的是以u字母打头的单词，如useful，university等，其第一个音标是［j］，所以要特别予以注意。

　?。畚螅?I need a hour to finish this letter.

　　［正］ I need an hour to finish this letter.

　　［析］ 要注意hour和honest的第一个字母不发音。

　?。畚螅?My teacher is a unknown man, but he is a very good man.

　?。壅?My teacher is an unknown man, but he is a very good man.

　?。畚觯?要注意以u打头的单词，它的发音为［］时，单数名词前要用an，如uncle等。

　　［误］ There is a f in the word football.

　　［正］ There is an f in the word football.

　　［析］ 英文字母单独使用时，如其第一个发音是元音时，其前面的不定冠词应该用an而不是a.

　?。畚螅?I have a little brother. He is a 8-year-old boy.

　?。壅?I have a little brother. He is an 8-year-old boy.

　?。畚觯?要注意这些字母的第一个发音为元音，如eight, eleven等。

　　2. able

　?。畚螅?This bike is able to be repaired.

　?。壅?This bike can be repaired.

　?。畚觯?be able to 主要表达某事或某人具有某种能力去作某事，应译为有本领有能力可以作某事，如：Im able to swim across this river. 而can可以用来表示具有接受能力或吸收能力。如：This radio can be repaired here.

　　3. about

　　［误］ This class is about to begin just now.

　?。壅?This class is about to begin.

　　［析］ 要注意be about to 是将要的意思，含有将来时之意，不要与表示过去时的时间状语连用。另外，be about to 一般用作书面语，对应的口语是be going to.

　　about on

　　about与on都可以作关于讲，但却有所不同，例如：This book is about physics. 应译为这是一本关于物理学的科普读物。而：This book is on physics.则应译为这是一本物理学方面的专著。

　　4. above

　?。畚螅?The temperature is five degrees over zero.　

　?。壅?The temperature is five degrees above zero.

　?。畚觯?表达在上方时，above与over是可以互换的，如：The sky is above (or over) our heads. 但是要表达在垂直方向上的上方时则应用above不可用over，如：The sun has risen above the horizon.

　?。畚螅?There is often thick cloud above the South of China in summer.

　?。壅?There is often thick cloud over the South of China in summer.

　　［析］ 当表达覆盖之意时，只可用over而不能用above.

　　［误］ There is a bridge above the river.

　?。壅?There is a bridge over the river.

　　［析］ 用来表达从上方越过时不能用above只能用over，如：The plane flew over the city. 但要注意There is waterfall above the bridge. 则应译为在桥的上游有一个瀑布。

　　5. across

　?。畚螅?He ran across the wood.

　　［正］ He ran through the wood.

　?。畚觯?across是指某一动作在一平面内进行，而through则是指该动作在一三维立体空间的运动过程。如：The man came in through the window. He walked across the square.

　　across的主要用法有两个。其一，意为对面，如：There is a school just across the street. 其二，意为横过，如：He walked across the street.

　　6. afraid

　?。畚螅?I dontt afraid of him.

　?。壅?I am not afraid of him.

　　［析］ 要注意害怕afraid一词在英语中不是动词，而是形容词，要与be动词连用。

　　7. after

　?。畚螅?Two weeks after he left.

　?。壅?Two weeks later he left.

　　［正］ He left after two weeks.　

　　［析］ 要表达在多少时间之后，英语中有两种表达法，即：用later时，要时间在前，如three hours later; 而用after时要时间在后，如after three hours.

　　［误］ My father will be back after a few hours.

　　［正］ My father will be back in a few hours.

　?。畚觯?受中文的影响，这个介词常常被误用。当你要表达在一段时间内某个动作可以完成时，一定要用in，而不能用after，因为after是指在某一时间之后。例如：This work will be done in two days. 即表明在两天内这一工作一定会做完。而如用了after，即表示在两天之后，完成的时间是不确定的。

　　after behind

　　after多用于表示顺序的前后，如：She walked in the line after Tom. 或用来表示追赶，表示一种动态，如：He ran after Mary. 而behind多用于强调先进与落后，如：She is much behind the other girls in sewing. 或者用于表达迟于，如：The train was ten minutes behind the time table. 或者与表示静态的动词连用，如：She hid herself behind the flowers.

　　8. afternoon

　?。畚螅?He worked very hard in a hot afternoon.

　?。壅?He worked very hard on a hot afternoon.

　　［析］ 习惯用的词组in the afternoon, 如果加入任何修饰词后其前面的介词in都要改为on，不论其修饰词在前还是在后，如：He swam in this river on the afternoon of June lst. 又如：Are you free on Sunday afternoon?

　　9. against

　?。畚螅?He against me.

　?。壅?He is against me.

　　［析］ 要注意against意为反对，但它在英文中却不是动词，而是介词，如要讲反对某事或某人时则要加动词be, 如：He is against somebody / something.

　　against for

　　against意为反对、不赞成；而for则意为同意，为其反意词。如：Are you for or against the plan?

　　10. age

　?。畚螅?He is twenty years old of age.

　?。壅?He is twenty.

　　［正］ He is twenty years old.

　?。壅?He is at the age of twenty.

　　1. a

　　［误］ I think it is an useful English dictionary.

　?。壅?I think it is a useful English dictionary.

　　［析］ 在不定冠词a与an的用法中要注意的一点是：an用在以元音开头的词之前；而a则用在以辅音开头的词之前。要特别注意的是以u字母打头的单词，如useful，university等，其第一个音标是［j］，所以要特别予以注意。

　?。畚螅?I need a hour to finish this letter.

　?。壅?I need an hour to finish this letter.

　?。畚觯?要注意hour和honest的第一个字母不发音。

　?。畚螅?My teacher is a unknown man, but he is a very good man.

　　［正］ My teacher is an unknown man, but he is a very good man.

　　［析］ 要注意以u打头的单词，它的发音为［］时，单数名词前要用an，如uncle等。

　　［误］ There is a f in the word football.

　　［正］ There is an f in the word football.

　?。畚觯?英文字母单独使用时，如其第一个发音是元音时，其前面的不定冠词应该用an而不是a.

　?。畚螅?I have a little brother. He is a 8-year-old boy.

　　［正］ I have a little brother. He is an 8-year-old boy.

　?。畚觯?要注意这些字母的第一个发音为元音，如eight, eleven等。

　　2. able

　　［误］ This bike is able to be repaired.

　　［正］ This bike can be repaired.

　?。畚觯?be able to 主要表达某事或某人具有某种能力去作某事，应译为有本领有能力可以作某事，如：Im able to swim across this river. 而can可以用来表示具有接受能力或吸收能力。如：This radio can be repaired here.

　　3. about

　?。畚螅?This class is about to begin just now.

　?。壅?This class is about to begin.

　?。畚觯?要注意be about to 是将要的意思，含有将来时之意，不要与表示过去时的时间状语连用。另外，be about to 一般用作书面语，对应的口语是be going to.

　　about on

　　about与on都可以作关于讲，但却有所不同，例如：This book is about physics. 应译为这是一本关于物理学的科普读物。而：This book is on physics.则应译为这是一本物理学方面的专著。

　　4. above

　　［误］ The temperature is five degrees over zero.　

　?。壅?The temperature is five degrees above zero.

　?。畚觯?表达在上方时，above与over是可以互换的，如：The sky is above (or over) our heads. 但是要表达在垂直方向上的上方时则应用above不可用over，如：The sun has risen above the horizon.

　　［误］ There is often thick cloud above the South of China in summer.

　?。壅?There is often thick cloud over the South of China in summer.

　　［析］ 当表达覆盖之意时，只可用over而不能用above.

　?。畚螅?There is a bridge above the river.

　?。壅?There is a bridge over the river.

　?。畚觯?用来表达从上方越过时不能用above只能用over，如：The plane flew over the city. 但要注意There is waterfall above the bridge. 则应译为在桥的上游有一个瀑布。

　　5. across

　?。畚螅?He ran across the wood.

　　［正］ He ran through the wood.

　?。畚觯?across是指某一动作在一平面内进行，而through则是指该动作在一三维立体空间的运动过程。如：The man came in through the window. He walked across the square.

　　across的主要用法有两个。其一，意为对面，如：There is a school just across the street. 其二，意为横过，如：He walked across the street.

　　6. afraid

　?。畚螅?I dontt afraid of him.

　?。壅?I am not afraid of him.

　?。畚觯?要注意害怕afraid一词在英语中不是动词，而是形容词，要与be动词连用。

　　7. after

　?。畚螅?Two weeks after he left.

　?。壅?Two weeks later he left.

　?。壅?He left after two weeks.　

　　［析］ 要表达在多少时间之后，英语中有两种表达法，即：用later时，要时间在前，如three hours later; 而用after时要时间在后，如after three hours.

　?。畚螅?My father will be back after a few hours.

　?。壅?My father will be back in a few hours.

　?。畚觯?受中文的影响，这个介词常常被误用。当你要表达在一段时间内某个动作可以完成时，一定要用in，而不能用after，因为after是指在某一时间之后。例如：This work will be done in two days. 即表明在两天内这一工作一定会做完。而如用了after，即表示在两天之后，完成的时间是不确定的。

　　after behind

　　after多用于表示顺序的前后，如：She walked in the line after Tom. 或用来表示追赶，表示一种动态，如：He ran after Mary. 而behind多用于强调先进与落后，如：She is much behind the other girls in sewing. 或者用于表达迟于，如：The train was ten minutes behind the time table. 或者与表示静态的动词连用，如：She hid herself behind the flowers.

　　8. afternoon

　?。畚螅?He worked very hard in a hot afternoon.

　?。壅?He worked very hard on a hot afternoon.

　　［析］ 习惯用的词组in the afternoon, 如果加入任何修饰词后其前面的介词in都要改为on，不论其修饰词在前还是在后，如：He swam in this river on the afternoon of June lst. 又如：Are you free on Sunday afternoon?

　　9. against

　　［误］ He against me.

　　［正］ He is against me.

　　［析］ 要注意against意为反对，但它在英文中却不是动词，而是介词，如要讲反对某事或某人时则要加动词be, 如：He is against somebody / something.

　　against for

　　against意为反对、不赞成；而for则意为同意，为其反意词。如：Are you for or against the plan?

　　10. age

　?。畚螅?He is twenty years old of age.

　　［正］ He is twenty.

　?。壅?He is twenty years old.

　　［正］ He is at the age of twenty.