I'm doing an example JLPT test, and I came across a sentence which required a blank to fill in. The correct version (according to the answer sheet) of the sentence is:
Now, another option, which seemed correct to me was:
Why is the 2nd form incorrect? I always thought I can just drop the い and add そうです to the stem. Why do I have to transform the adjective into noun here? Thanks for clearing that for me.