怎样的单词要双写末字母再加ing?

1、以重读闭音节结尾，末尾只有一个辅音字母的动词，要双写这一辅音字母，再加-ing。例如：run-running, swim-swimming等。2、以-al,-er,-ill结尾的动词，即使重音不在最后一个音节上，也要双写，再加-ing 如：travelling等。可以加动词ing的①及物动词。She likes drawing very much.；②某些短语动词。 Mary is thinking of going back to New York.；③ do+限定词（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介词：Her sister is good at learning physics.；⑤形容词worth, busy等：This book is well worth reading. –ing作宾语带有宾语补足语时，要用it作为形式宾语，而将作宾语的-ing后置，如：We found it no good talking like that. Do you think it necessary trying again?

我知道一条就是一个单词的最后一个字母的前面有一个元音字母就双写加ing，如果有两个就不用双写，直接加ing。

1、以重读闭音节结尾，末尾只有一个辅音字母的动词，要双写这一辅音字母，再加-ing。例如：run-running, swim-swimming等。2、以-al,-er,-ill结尾的动词，即使重音不在最后一个音节上，也要双写，再加-ing 如：travelling等。可以加动词ing的①及物动词。She likes drawing very much.；②某些短语动词。 Mary is thinking of going back to New York.；③ do+限定词（my, some, any, the等）+ -ing，表示“做…事”之意，如：We often do our cleaning on Saturday afternoon. Will you