Question

My skirt is red怎么改否定句(答案)？

Answer 1

肯定句改成否定句分两种情况：
1.有be动词的，直接在be动词后加否定词not，这个句子有be动词is，所以否定句应该是My skirt is not red
2.没有be动词的情况，借助助动词，在助动词后加not，实义动词用原型，比如说：My mom likes banana变成否定句为：My mom doesn't like banana.

Answer 2

my skirt is no red/ my skirt is redless.

Answer 3

my skirt isn't（is not）red.