1. 一般直接加ing, 如：playing,looking等 2. 不发音的e结尾的,去掉e, 加ing: have-- having; leave -- leaving 3. 以一个辅音字母结尾的重读闭音节,双写最后一个辅音字母,再加ing.这里的条件都必须满足：一个辅音字母结尾+重度音节+闭音节： stop （只有一个音节,通常看做重读音节）-- stopping begin （后面一个是重度音节） -- beginning 4,以i或ie结尾的,把i或ie换成y再加ing,如,lie lying,die dying等
什么情况下be要加ing
be动词后面加ing时表示进行时，当表示被动语态的时候不用加ing，要用过去分词形式。 例如：事/物人 +Be + 过去分词”以组成被动语态(The Passive Voice)，如以下句子：Her money in the drawer was stolen.A number of good jobs are taken up by foreigners.David studied in Taiwan but hasbeen trained as a language lecturer in America.Can all the wonderful birds be found in our Bird Park.The disobedient boywas told to stand out- side the classroom.Steps are being taken to reduce traffic con- gestion during peak hours.Dishonest students will be immediately dealt with.