When you learn an adjective, pay attention to which kind it is. Most of the い adjectives end with い, such as おいしい (delicious)、かなしい (sad)、ただしい (correct)、たかい (tall or expensive) -- you probably get the idea. There are only a couple that end with い that are actually な adjectives. One is きれい(pretty). The thing to remember is that い adjectives will conjugate for present and past, positive and negative. If you get it wrong, people will usually still understand what you're trying to say. You'll get the hang of it with practice. Here's a website that might help. http://www.guidetojapanese.org/learn/grammar/adjectives Good luck with your studies!