一.动词ing形式的用法
1.动词的-ing形式可直接置于句首作主语。
Seeing is believing.
百闻不如一见du。
2.一些特殊表达..如: be good at doing sth
enjoy doing sth.
be busy doing
feel like doing
thank you for doing
do some cooking/cleaning/reading/shopping/washing
go swimming/fishing/shopping/skating/boating
二.动词现在分词由动词原形在词尾加构成
1)一般情况下直接加ing think---thinking sleep---sleeping
study---studying speak---speaking
carry---carrying say---saying
2)以不发音的字母e结尾的单词，去掉字母e，再加ing
wake---waking make---making come---coming
take---taking leave---leaving have---having
3)以重读闭音节结尾，呈现“辅，元，辅”结构的动词，先双写末尾的辅音字母，再加ing 。初中学过的这类词有：begin，cut, get, hit, run, set, sit, spit, stop, swim, beg, drop, fit, nod, dig, forget, regret, rid, 等。 (visit 不是以重读闭音节结尾，不用双写)
travel虽然重读第一音节，词尾音节不重读，但是现在分词仍要双写末尾辅音字母，然后再加ing ，如：travel---travelling.初中阶段此类词只有这一个。
动词ing形式的变化规则
现在进行时: am,are,is +动词ing(表示正在进行的动作)动词ing的变化规则：１．一般情况直接＋ing例:sweep-sweeping read-reading2．重读闭音节一个辅音字母结尾，双写辅音字母＋ing例：shop-shopping sit-sitting swim-swimming
