1、以重讀閉音節(jié)結(jié)尾,末尾只有一個(gè)輔音字母的動(dòng)詞,要雙寫這一輔音字母,再加-ing.例如：run-running,swim-swimming等.2、以-al,-er,-ill結(jié)尾的動(dòng)詞,即使重音不在最后一個(gè)音節(jié)上,也要雙寫,再加-ing 如：travelling等.可以加動(dòng)詞ing的①及物動(dòng)詞.She likes drawing very much.；②某些短語(yǔ)動(dòng)詞.Mary is thinking of going back to New York.；③ do+限定詞（my,some,any,the等）+ -ing,表示“做…事”之意,如：We often do our cleaning on Saturday afternoon.Will you do any shopping on Saturday this afternoon?④介詞：Her sister is good at learning physics.；⑤形容詞worth,busy等：This book is well worth reading.–ing作賓語(yǔ)帶有賓語(yǔ)補(bǔ)足語(yǔ)時(shí),要用it作為形式賓語(yǔ),而將作賓語(yǔ)的-ing后置,如：We found it no good talking like that.Do you think it necessary trying again?