动词的三单变化规律,现在分词变化规律,过去式变化规律

规则动词的过去式由“动词原形+-ed”构成,具体变化有：
1.直接在词尾加-ed.如:want—wanted,work—worked,need—needed,clean—cleaned
2.以不发音的e结尾的在词尾加-d.如：like—liked,live—lived,use—used,move—moved
3.以一个元音字母加一个辅音字母结尾的重读闭音节动词,先双写结尾的辅音字母,再加-ed.如：stop—stopped,trip—tripped
4.以辅音字母加y结尾的动词,先把y变成i,再加-ed.如：study—studied,carry—carried,hurry—hurried,marry—married
不规则动词的过去式见课本后的不规则动词表.大体上归纳有以下六条记忆法：
1.以t结尾的词,过去式与原形相同.如：put—put,let—let,cut—cut,beat—beat
2.以d结尾的词,把d变成t.如:build—built,lend—lent,send—sent,spend—spent
3.以n结尾的词,在词后加t.如：mean—meant,burn—burnt,learn—learnt
4.以ow / aw结尾的词,把ow / aw变成ew.如：blow—blew,draw—drew,know—knew,grow—grew
5.含有双写字母的词,将双写改为单写,在词尾加t.如：keep—kept,sleep—slept,feel—felt,smell—smelt
6.含有元音字母o / i的词,将o / i变成a.如：sing—sang,give—gave,sit—sat,drink—drank
规则动词词尾加-ed有三种读音：
1.在清辅音后读作[t].如：asked,helped,watched,stopped
2在浊辅音和元音后读作[d].如：enjoyed,studied,moved,called
3.在t / d后读作[id].如：wanted,needed
现在分词的构成方法如下 ：一般情况下,直接在动词原形后面加 -ing.
going asking finding working being seeing printing raining standing studying speaking spelling
以不发音的-e 结尾的动词,去-e ,再加-ing.coming taking firing encircling writing becoming breathing leaving
闭音节的单音节词,或以重读闭音节结尾的多音节词,这些词的末尾只有一个辅音字母时,双写这个辅音字母,再加 -ing.
sitting running getting cutting stopping beginning planning permitting
一般现在时主语单三人称时的动词变化
①在一般现在时中,当主语为第三人称单数时,动词要用“s”型（即第三人称单数形式）.
②所谓动词“s”型的构成,可按名词变复数的规则来记,即：
i）在动词尾直接加 s.如：
play—plays,want—wants,work—works,know—knows,help—helps,get—gets
ii）以字母s、x、ch或o结尾的动词加-es；如：
guess—guesses,fix—fixes,teach—teaches,brush—brushes,go—goes,do—does,watch—watches,catch—catches
iii）以辅音字母＋y结尾的动词,先变y为i,再加-es.如：
study—studies,carry—carries,fly—flies,worry—worries
③④强调如何将主语是第三人称单数的肯定句变为否定和疑问句.现举例说明（用划线部分来说明顺口溜）：
1）His mother works in a factory．
His mother doesn’t work in a factory．
Does his mother work in a factory?
2）Mr Li teaches us English．
Mr Li doesn’t teach us English．
Does Mr Li teach you English?
3）My brother studies maths well．
My brother doesn't study maths well．
Does your brother study maths well?