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
求以y结尾的动词-ing形式没什么特殊的变化,直接加ing