1、一般现在时
表示普遍、经常性的或长期性的动作时使用一般现在时，它有：
Be 动词：She’s a worker. Is she a worker? She isn’t a worker.
情态动词：I can play the piano. Can you play the piano? I can’t play the piano.
行为动词：They want to eat some tomatoes. Do they want to eat any tomatoes? They don’t want to eat any tomatoes.
Gina has a nice watch. Does Gina have a nice watch? Gina doesn’t have a watch.
2、现在进行时
表示动词在此时正在发生或进行就使用进行时态，结构为sb be v-ing sth + 其它.
I’m playing baseball. Are you playing baseball? I’m not playing baseball.
Nancy is writing a letter. Is Nancy writing a letter? Nancy isn’t writing a letter.
They’re listening to the pop music. Are they listening the pop music? They aren’t listening to the pop music.
