I posted a sentence to be corrected which was:
and they told me to use 「嫌い」 instead of 「不味い」.
What is the difference between the two when it comes to food?
私は辛い野菜が嫌い makes sense because this is the grammar pattern used to talk about things you like or do not like.
I think it's important to note that both 嫌い and 好き are nouns.
Really, they are nominalized verbs,
You might think of the Japanese grammar as saying something like,
私は辛い野菜が不味い is incorrect because this is not the grammar pattern used to talk about whether you think something is tasty or not. 不味い is an i-adjective, meaning "bad tasting".
The correct grammar pattern for telling someone what you think is tasty or not (assuming you want to use 私は) would be,
If you don't say the と思う part, then it is similar to saying "I have spicy vegetables taste bad" in English.
There are two ways to fix this, either remove "I" and change the topic to "spicy vegetables" or add "think"...