可数名词单数变复数的规则:1.一般在词尾加-se.g.map-maps;book-books2.以字母s,x,sh,ch结尾的加-ese.g.bus-buses;box-boxeschurch-churches;dish-dishes3.以辅音字母+o结尾的加-ese.g.hero-heroes;potato-potatoestomato-tomatoes4.辅音字母+y结尾的,变y为i,再加-es.e.g.story-stories;baby-babies5.以字母-f或-fe结尾的,变-f,-fe为-v再加-ese.g.life-lives;leaf-leaves;wolf-wolves;thief-thieves以下词例外:roof-roofs;chief-chiefs动词的第三称单数变化规则:在一般现在时中,当主语是第三人称单数形式时,行为动词用第三人称单数形式1.一般在词尾加-se.g.help-helps;play-plays2.以字母s,x,sh,ch,o结尾的加-ese.g.miss-misses;fix-fixeswash-washes;teach-teachesdo-does;go-goes3.辅音字母+y结尾的,变y为i,再加-es.e.g.study-studies;try-tries特殊变化:have-has;动词过去式变化规则:1.一般在词尾加-ede.g.play-played;look-looked2.以不发音的字母e结尾的加-de.g.arrive-arrived;3.辅音字母+y结尾的,变y为i,再加-ed.e.g.cry-cried;carry-carried4.重读闭音节,且末尾只有一个辅音字母的,双写辅音字母加-ede.g.stop-stopped;动词现在分词变化规则:1.一般在词尾加-inge.g.sleep-sleeping;look-looking2.以不发音的字母e结尾的去e加-inge.g.arrive-arriving;take-taking3.重读闭音节,且末尾只有一个辅音字母的,双写辅音字母加-inge.g.run-running;swim-swimming特殊变化:die-dying;lie-lying;tie-tying形容词的比较级和最高级变化形式规则:1.一般在词尾加-er和-este.g.long-longer-longest2.以不发音的字母e结尾的加-r和-ste.g.large-larger-largest3.辅音字母+y结尾的,变y为i,再加-er和-este.g.happy-happier-happiest4.重读闭音节,且末尾只有一个辅音字母的,双写辅音字母加-er和-este.g.big-bigger-biggest5.部分双音节和多音节词都在前面加单词more和moste.g.difficult-moredifficult-mostdifficult