The way my teacher taught it was that all adjectives that end in the character 'i' (sorry this computer doesn't have Japanese characters) are i adjectives except kirai and anything that ends in -ei, like kirei or yuumei. This was when I was just starting Japanese however, I'm not sure how well it holds for very advanced words, but I haven't found another exception yet.
The way my teacher taught it
The way my teacher taught it was that all adjectives that end in the character 'i' (sorry this computer doesn't have Japanese characters) are i adjectives except kirai and anything that ends in -ei, like kirei or yuumei. This was when I was just starting Japanese however, I'm not sure how well it holds for very advanced words, but I haven't found another exception yet.