动词变现在分词和变过去式规律

分析： 

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.如： 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  

规则动词的过去式由“动词原形+-ed”构成,具体变化有：  

直接在词尾加-ed.如: want—wanted, work—worked, need—needed, clean—cleaned  

 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