一般情况,直接+ing,例：work,working
以不发音的e结尾,去e+ing,例：hope,hoping；write,writing
以ie结尾,去ie变y+ing,例：die,dying；lie,lying；tie,tying
以重读闭音节结尾,末尾只有一个辅音字母的动词,双写辅音字母+ing,例：begin,beginning；swim,swimming；run,running