A. 一般加-ing
work -- working
study -- studying
B. 以e 结尾的词去e后加-ing
live -- living
write -- writing
C. 动词为单音节:以单一元音字母+单一辅音字母结尾,辅音字母双写,再加ing;动词为双音节或者多音节:最后一个音节为重读音节,以单一元音字母+单一辅音字母结尾,辅音字母双写,再加 ing
stop -- stopping
run -- running
swim -- swimming
begin -- beginning