Question

Tom+takes+off+his+coat改为否定句？

Answer 1

Tom doesn’t take off his coat.
从takes可知这是一般现在时。一般现在时动词形式为do原形/does单三，be动词形式为am/is/are，如：
I love you. 我爱你（原形love）
She loves you.她爱你（单三loves）
I am a boy.我是个男孩。
She is a girl. 她是个女孩。
Mary is a girl.玛丽是个女孩。
This girl is my little sister.这个女孩是我妹妹。
you are a boy.你是个男孩。
You are boys. 你们是男孩。
Tom是单数第三人称，所以谓语动词take off用了单三形式，在take后加s。
完成否定要用助动词+not+动词原形，同样选择单三形式的does，does not缩写为doesn’t，后面接动词原形take。

Answer 2

1 When , go
2 What is , doing
3 What do they like doing ?
/
When do they like skating ?
4 aren't planting
5 is taking