I'm watching TV. 1.My sister often plays the piano. 2.He exercises every day.3. I always do my homework after school. 观察下列三组句子的区别(从表达意思、动词形式与时间状语等面） Listen, my sister is playing the piano .Look, he is exercising. I am doing my homework now. 一般现在时 一般现在时表示:主语经性和习惯性的动作或存在的状态，也表示说话者的及自然现象。例如：1.She is a good musician.2.Mary can speak English well.3.The earth(地球)is round(圆的) . 用的时间状语主要有：always，usually，often，sometimes，never，every day，in the morning/afternoon/evening，after school/dinner等； ?1. 现在进行时态表示现在(说话瞬间)正在进行 或发生的动作。如: look, the students are listening to the teacher. He is watching TV now. 现在进行时态还可以表示当前一时间内的活动 或现阶正在进行的动作。如: We are working at school these days . I am writing a book this week.现在进行时与现在进行时态连用的词:now, listen, look等。 2. 现在进行时由be(am/is/are)+动词-ing形式构成。 肯定式结构: 主语+be+动词-ing形式+其他. 否定式结构: 主语+be+not+动词-ing形式+其他. 一般疑问句结构: Be+主语+动词-ing形式+其他？ 特殊疑问句结构: 疑问词+be+主语+其他？3. 动词-ing形式的构成注意: 以”ie”结尾，要变“ie”为“y”, 再加-ing. 如：die—dying(死）lie—lying(平躺）。writetakehavemakecome arrivedanceleave动词现在分词变变变writingtakinghavingmakingcomingarrivingdancingleavingsitshopcutstopputgetbe |
