現(xiàn)在進(jìn)行時：主語+am/is/are +動詞ing形式構(gòu)成.
一般現(xiàn)在時：主+BE動詞（am, is, are）+表語或主語+動詞原形+其它
一般過去時：主語+動詞的過去式+賓語+其他結(jié)構(gòu)
現(xiàn)在完成時主語：主語＋have/has+過去分詞
過去進(jìn)行時：主語+助動詞was/were + 現(xiàn)在分詞多點啊~~例句分別是：They are playing basketball now.現(xiàn)在他們正在打籃球。The teacher is not in the classroom and the students are very noisy.老師不在教室，學(xué)生都很吵鬧。The children had a good time in the park.孩子們在公園里玩的很開心。I have just turned off the light. 我剛剛把燈關(guān)上。I was doing my homework at 9 p.m. last Sunday.上個星期天九點鐘我正在做作業(yè)。