八年级英语上册语法知识点: 形容词/副词的比较级和最高级1. 形容词/副词的比较级和最高级的构成规则(1)单音节词和少数以-er,-ow结尾的双音节单词,比较级在后面加-er,最高级在后面加-est。① 单音节单词small→smaller→smallestshort→shorter→shortesttall→taller→tallestgreat→greater→greatest②少数以-er,-ow结尾的双音节单词clever→cleverer→cleverestnarrow→narrower→narrowest(2)以不发音e结尾的单音节单词,比较级在原形后加-r,最高级在原级后加-st。large→larger→largestnice→nicer→nicestable→abler→ablest(3)以一个辅音字母结尾的闭音节(即:辅音+元音+辅音)单词中,先双写末尾的辅音字母,比较级加-er,最高级加-est。big→bigger→biggesthot→hotter→hottestfat→fatter→fattest(4)以“辅音字母+y”结尾的双音节词, 把y改为i,比较级加-er,最高级加-est。easy→easier→easiestheavy→heavier→heaviestbusy→busier→busiesthappy→happier→happiest(5)其他双音节词和多音节词,比较级在前面加more,最高级在前面加most。beautiful→more beautiful→most beautifuldifferent→more different→most differenteasily→more easily→most easily(6)有少数形容词、副词的比较级和最高级是不规则的,必须熟记。good→better→bestwell→better→bestbad→worse→worstill→worse→worstold→older/elder→oldest/eldestmany/much→more→mostlittle→less→leastfar →further/farther→ furthest/farthest2. 形容词和副词比较级的用法(1)“甲+be+(倍数)+形容词比较级+than+乙”表示“甲比乙…”或“甲比乙…几倍”。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。(2)“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”。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。3. 形容词和副词最高级的用法(1)“主语+be+the+形容词最高级(+单数名词)+in/of...”表示“……是……中最……的”。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。(2)“主语+实意动词+(the)+副词最高级+in/of...”表示“……是……中最……的”。I jump (the) farthest in my class.我是我们班跳得最远的。