英语单词中哪些动词边-ing要结尾双写,哪些变-ed要结尾双写

1．英语动词加-ing,通常是在原形词尾直接加-ing构成：cough—coughing,climb—climbing,stand—standing,fight—fighting
2．以-e结尾的动词
（1）如果动词原形以一辅音加一不发音的-e结尾,一般应去掉e再加ing：
write—writing,hope—hoping,care—caring,stare—staring,plane—planing,have—having,save—saving,produce—producing,breathe—breathing
（2）以-ie结尾的动词应先将e去掉,将i变成y然后再加-ing：
die—dying,tie—tying,vie—vying,lie—lying
（3）以-ee,－oe,－ye结尾的动词加-ing时应保留词尾e：
see—seeing,flee—fleeing,free—freeing,agree—agreeing,hoe—hoeing,dye—dyeing,eye—eyeing
（4）以-ue结尾的动词大多应先去e再加-ing：
sue—suing,imbue—imbuing,construe—construing,pursue—pursuing,
rue—ruing
有时,词尾e可去掉也可保留：
glue—gluing或 glueing,cue—cuing或 cueing,blue—blueing或 bluing,
true—truing或trueing,clue—clueing或cluing
3．以一元音加一辅音结尾的动词
（1）如果动词最后一音节为重读闭音节,最后一个字母需要重复：
run—running,stop—stopping,hop—hopping,plan—planning,star—starring,control—controlling但辅音x是个例外,无需重复（x其实起着两个辅音的作用）：
tax—taxing,relax—relaxing
（2）如果动词最后一个音节为次重读音节,最后一个字母有时也重复：
kidnap—kidnapping或kidnaping,program—programming或programing
（3）如果动词最后一个音节为非重读音节,最后一个字母大多无需重复：
open—opening,offer—offering,audit—auditing但在有些动词中,重复或不重复均可：
worship—worshiping或 worshipping,focus—focusing或 focussing,cancel—canceling或cancelling,travel—traveling或travelling
以非重读的-el结尾的动词加-ing时,英国英语习惯于重复词尾l,而美国英语则习惯于不重复1.
4．若动词以一元音加一半元音（y或w）结尾,可直接加-ing：
pay—paying,throw—throwing,follow—following,draw—drawing,employ—employing
5．以-ic结尾的动词应先在字母c后加一字母k再加-ing：
frolic—frolicking,panic—panicking,mimic—mimicking,picnic—picnicking,traffic—trafficking
这主要是为在动词后加-ing之后保留/k/这个音.若不在字母c后加字母k而直接加-ing,字母 c的发音就不再是/k/,而是/s/：
ed的加法和ing的类似.