现在进行时和过去进行时讲解与练习

现在（正在）进行时2015. 7.17【定 义】 现在（正在）进行时表示说话的瞬间正在进行或发生的事情。如： They are singing and dancing happily now . 他们正在高兴地唱歌跳舞。She is showing her friend around the city . 她正在带一位朋友游览城市。【结 构】 主语 + be（ am / is / are）+动词的 -ing 形式 。肯定句形式：I + am 动词 ing. 如：I am reading (read) an interesting story book now.She/He/It + is 动词 ing. 如：Tom is reading (read) an interesting story book now.We/You/They + are动词 ing. 如：They are reading (read) an interesting story book now.否定句形式：直接在 be（am, is, are ）之后加 not，其余照抄。如: I am not reading ( not read) an interesting story book now. Tom isn ’t reading ( not read) an interesting story book now. They aren ’t reading ( not read) an interesting story book now.一般疑问句：直接将 be（am, is, are ）提到主语之前，其余照抄。如： Is Tom reading (read) an interesting story book now? Are they reading (read) an interesting story book now?特殊疑问句： 首先分析划线部分的意思，确定用哪个疑问词（what, where, who, when, which, whose, how, how many, how much, what shape, what colour, what ⋯ doing, where ⋯ going, what ⋯ do）,然后再将原句变为一般疑问句形式（即将be动词提到主语之前，其余的不变）。如： What time is Tom reading(read) an interesting story book? Where are they taking(take) pictures? 现在进行时的时间标志短语汇总：现在（正在）进行时常与一些固定的时间短语搭配使用：① now“现在”如: Jim is playing soccer now. ② Look! Listen! “看啊！听啊！”如： Look! Mr. Lee is working on the computer. Listen! The birds are sing in the tree. ③ right now= at the moment “此刻”如： The monkeys are climbing up the trees at the momnet. ④Where is ⋯? 问题的回答，暗指说话的时候。如：— Where is your mom, Tom? — Oh, she is cooking in the k...