八年级上册units 4--6知识归纳
一、词语辨析：
1、arrive, get, reach
arrive不及物动词，后面要跟in或at。表示到达大城市或国家时要用in，而到达小城市、乡村、车站等小地方则用at。如:
we arrived in london last week. 我们上周到达伦敦。
the doctor arrived at the village at last. 医生终于到达了那个村子。
reach是"独行侠"，是及物动词，后面从来不跟介词，直接跟宾语(地点名词)就行了。如:
when did you reach the station? 你是什么时间到达车站的?
he reached nanjing at noon. 他是中午到达南京的。
get是不及物动词后面要接to再接地点名词，.当“到达”的地点是副词时，就不带它了。如:
ann got to the farm at six o‘clock. 安六点钟到达农场.
i got here early in the morning. 我一大早就到这儿了.
注意：如果不指明到达的地点就不能用get，而要用arrive.如:
when i arrived, they weren‘t there. 当我到达时,他们不在那儿.
2、sick, ill
（1）都可译为“生病的”。ill只在系动词后作表语：
her mother was ill in bed. she feels ill today.
但sick既可作表语： her mother was sick / ill in bed. （作表语常是美国英语用法）
也可作定语（即后接名词）：jane is taking care of her sick mother.
(此处是定语，不可用ill. 原因见下文ill用法)
（2）若ill作定语，译为“坏的，恶劣的”an ill person一个坏人
sick作表语时也常译为“恶心的，想吐的”。
the boy always feels sick when he travels by car.
3、other, another, the other
another与the other 和others 与the others都来源于other这个词。
其用法是:
another泛指三个或三个以上的人或物中没有确定的另一个；
another+数字+名词= 数字+more+名词；
the other则指已知的两个人或两事物中的另一个。(one…,the other….)
others或 other+ 名词，泛指“别的人或别的物”；
the others指“一定范围内的其余的人或物”。
注意:若强调确定数目中的“一(几)个”与其余的,用one...the others或“the other +复数名词”结构。
经典考例:
1) shanghai is really a fascinating city and weve decided to stay for ________ two weeks. (上海卷)
a. another b. other c. the other d. other’s
2) if you want to change for a double room you’ll have to pay ________ $15.(nmet )
a. another b. other c. more d. each
3) one of the sides of the board should be painted yellow, and ________ . (京、皖春季卷)
a. the other is white b. another white c. the other white d. another is white
4) sarah has read lots of stories by american writers. now she would like to read ________ stories by writers from ________ countries.(nmet ’97)
a. some; any b. other; some c. some; other d. other; other
5) -have you finished your report yet?
-no, i’ll finish in ________ ten minutes.(nmet ’95)
a. another b. other c. more d. less
keys：aacca
二、形容词，副词的比较级、最高级
（一）、规则变化
1.一般在词尾直接加er或est，例如，tall-taller-tallest，long-longer-longest
2.以不发音的字母e结尾的单词在词尾直接加r或st，例如，nice-nicer-nicest
3.以辅音字母+y结尾的词，把y变为i，再加er或est，例如，heavy-heavier-heaviest
4.重读闭音节，末尾只有一个辅音字母，双写这个辅音字母，再加er或est，例如，big-bigger-biggest
5.部分双音节词和多音节词分别在原级前加more构成比较级和most构成最高级，例如，slowly-more slowly-most slowly；beautiful-more beautiful-most beautiful
（二）、形容词，副词等级的用法
a、原级的用法
1.只能修饰原级的词，very，quite，so，too
例如，he is too tired to walk on.他太累了以至于不能再继续走了。
my brother runs so fast that i can‘t follow him.我弟弟跑得那么快以至于我跟不上他。
2.原级常用的句型结构
(1)“甲+be+(倍数)+as+形容词原级+as+乙”表示“甲和乙程度相同”或“甲是乙的几倍”
例如，tom is as old as kate.汤姆和凯特年龄一样大。
tom is twice as old as kate.汤姆的年龄是凯特的二倍。
“甲+实意动词+(倍数)+as+副词原级+as+乙”表示“甲和乙程度相同”或“甲是乙的几倍”
例如，tom runs as fast as mike.汤姆和迈克跑得一样快。
tom runs twice as fast as mike.汤姆跑得速度是迈克的二倍。
(2)“甲+be+not+as/so+形容词原级+as+乙”甲不如乙…
例如，this room is not as/so big as that one. 这个房间不如那个大。
“甲+助动词+not+动词原形+as/so+副词原级+as+乙”甲不如乙…
例如，he doesn’t walk as slowly as you.他走路不像你那样慢。
b、比较级的用法
1.可以修饰比较级的词，much，a lot，far，…的多a little，a bit，…一点儿 even甚至，still仍然
例如，lesson one is much easier than lesson two.第一课比第二课容易得多。
tom looks even younger than before.汤姆甚至比以前更年轻。
this train runs much faster than that one.这辆火车比那辆跑地快。
she drives still more carefully than her husband.她开车仍然比她丈夫还认真。
2.比较级常用的句型结构
(1)“甲+be+(倍数)+形容词比较级+than+乙”表示“甲比乙…”或“甲比乙…几倍”
例如，tom is taller than kate.汤姆比凯特高。
this room is three times bigger than that one.这个房间比那个大三倍。
“甲+实意动词+(倍数)+副词比较级+than+乙”表示“甲比乙…”或“甲比乙…几倍”
例如，i got up earlier than my mother this morning.我今天早晨起床比我妈妈还早。
he runs three times faster than his brother.他跑的速度比他弟弟快三倍。
(2)“甲+be+形容词比较级+than+any other+单数名词(+介词短语)”表示“甲比同一范围的任何一个人/物都……”，含义是“甲最……”。
例如，the yangtze river is longer than any other river in china.
=the yangtze river is longer than any of the other rivers in china.长江比中国的任何一条其他的河都长。
=the yangtze river is longer than the other rivers in china.长江比中国的其他所有的河都长。
=the yangtze river is the longest river in china.长江是中国最长的河流。
注意：the yangtze river is longer than any river in japan.长江比日本的任何一条河都长。
“甲+实意动词+副词比较级+than+anyother+单数名词(+介词短语)”表示“甲比同一范围的任何一个人/物都……”，含义是“甲最……”。
例如，mike gets to school earlier than any other student in his class.
= mike gets to school earlier than any of the other students in his class.迈克比他们班上任何一个其他的同学到校都早。
= mike gets to school earlier than the other students in his class.迈克比他们班上其他的同学到校都早。
= mike gets to school earliest in his class.迈克在他们班到校最早。
注意：mike gets to school earlier than any student in tom’s class.迈克比汤姆班上任何一个学生到校都早。(迈克和汤姆不是同一个班)
(3)“甲+be+the+形容词比较级+of the two+……”表示“甲是两者中较……的”。
例如，look at the two boys. my brother is the taller of the two.看那两个男孩，我弟弟是两个当中较高的那个。
(4)“比较级+and+比较级”表示“越来越……”。
例如，he is getting taller and taller.他变得越来越高了。
the flowers are more and more beautiful.花儿越来越漂亮。
he does his homework more and more carefully.他做作业越来越认真了。
(5)“the+比较级，the+比较级”表示“越……，越……”。
例如，the more careful you are，the fewer mistakes you’ll make.你越认真，犯的错误越少。
(6)“特殊疑问词+be+形容词比较级，甲or乙？”
例如，which is bigger，the earth or the moon？哪一个大，地球还是月球？
“特殊疑问词+实意动词+副词比较级，甲or乙？”
例如，who draws better，jenny or danny？谁画得比较好，詹妮还是丹尼？
c、最高级常用句型结构
(1)“主语+be+the+形容词最高级+单数名词+in/of短语”表示“……是……中最……的”。
例如，tom is the tallest in his class./of all the students.汤姆是他们班上/所有学生当中最高的。
this apple is the biggest of the five.这个苹果是五个当中最大的。
“主语+实意动词+(the)+副词最高级+单数名词+in/of短语”表示“……是……中最……的”。
例如，i jump (the) farthest in my class.我是我们班跳得最远的。
(2)“主语+be+oneofthe+形容词最高级+复数名词+in/of短语”表示“……是……中最……之一”。
例如，beijing is one of the largest cities in china.北京是中国最大城市之一。
(3)“特殊疑问词+be+the+最高级+甲，乙，or丙？”用于三者以上的比较。
例如，which country is the largest，china，brazil or canada？哪一个国家最大，中国，巴西还是加拿大？
“特殊疑问词+be+the+副词最高级+甲，乙，or丙？”用于三者以上的比较
例如，which season do you like (the) best，spring，summer or autumn？你最喜欢哪一个季节，春天，夏天还是秋天？
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