Why are there kanjis written into hirakana? Hallo, I'm lerning Japanese by myself. And I'm always confused about when should I use kanji and when hirakana. Sometimes it is written as わたしは上海から来ました。 But sometimes it is written as 私は上海から来ました。 Even in my japanese book(みんなの日本語) there are these two different ways to write "I". I thought that I should always write in kanji when there is kanji for the word. But now it seems wrong. Is there a grammatical rule to talk about this? ありがとう！