Have you decided what to do next?中what为什么不能换成how?

Have you decided what to do next?中what为什么不能换成how? please tell me(what )you will (do with)next.为什么不能换成 how与 dea 是Have you decided ( ）on winter vacation?空格里为什么不能填what to do Have you decided _____the problem?A.what to do B.how to do w Have you decided what you want to do after school 英语翻译have you decided what we shall do next?对不?另外想问一下宾语从句中,如果 Have decided（ ） on winter vacation?这个句子括号中为什么不能用what to do? well,i have not decided what to do ..what ( ) you?2.i am goi how to do it next还是what to do next What do you ( ) to do next weekend? ---Have you decided what to do when you leave school?---Oh,y Have you decided what you want to do after school?want 是不是要改