读的方法和平假名一样，不过写的方法不一样 主要用在注明一些日语里面借用外语发音的时候写的东西（一般来说都是英语）

Katakana is a Japanese syllabary, one component of the Japanese writing system along with hiragana. Katakana is mostly used to write the foreign languages into Japanese. The Japanese scholars called it "loan words" Example: Juice, Boyfriend, Girlfriend etc., these words have to be written in Japanese using Katakana. Kanji are not loan words.