Kanji usually show the root meaning of the word. While nouns are usually written only with kanji, they can also be written in kana if they are very common words, like "sushi", or if their kanji is not well known, not part of the "jōyō kanji" (a standard list of 1,945 kanji all Japanese adults are expected to know) or too difficult to remember how to write, like "bara," whose kanji is 薔薇, but is usually only written as ばら in hiragana or as バラ in katakana. 