She is singing改为否定句是She isn't sinsing. 这是个把现在进行时的肯定句变成否定句的句型转换。把She is singing改成否定句，只需要在is后加 not，is not缩写成isn't即可，其它不变。再例如My mother is cooking for me(我妈在给我做饭)改成否定句是 My mother isn't cooking for me（我妈不在给我做饭).
温馨提示：
微信扫码关注公众号
获取更多考试热门资料
