现在进行时的结构
现在进行时由am / is / are + 现在分词构成。如：
Im studying at Yu Cai Senior Middle school. 我在育才中学读书。
He is writing on the desk. 他再课桌上写字。
They are talking about their visiting the Great Wall. 他们在谈论游长城的事情。
【说明】动词现在分词的构成方法：
(1) 一般在动词后加-ing。如：saysaying, playplaying, thinkthinking, studystudying, teach teaching, blowblowing, buildbuilding.
(2) 动词若以-e结尾, 则去e再加-ing。如：loveloving, makemaking, guideguiding, datedating.
(3) 在以单短元音的重读闭音节结尾，且末尾只有一个辅音字母的动词后，双写最后一个辅音字母，再加-ing。如：beginbeginning, regretregretting, planplanning, ban banning.
(4) 在以ie结尾的动词后，改ie为y，再加-ing。如：lielying, diedying, tietying.
(5) 在以-c[k] 结尾的动词后加-king。如：picnicpicnicking, panicpanicking.