Japanese Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Japanese language. It only takes a minute to sign up.
Sign up to join this community
From the first day I started to learn Japanese, I saw people use hiragana to help read kanji, they are usually written on the top of those kanjis.
But recently I also saw some Japanese use katakana, to not only spell and mimic the sound of the foreign words, but also write them on the top of kanji to aid in their reading, instead of hiragana.
Is this also okay or common practice? Are there any differences, or does it not matter?
What you're talking about is called furigana (振り仮名). It's normally written in hiragana script, except maybe in dictionaries sometimes when katakana is used to indicate the Chinese reading. Another case for using katakana as furigana is when you want to write a foreign pronunciation for a word written in kanji. The Wikipedia page for furigana gives the example of 一角獣 (one horn beast) with furigana "ユニコーン" (unicorn). But those are exceptions, in most cases, for difficult kanji, hiragana is used.
From my experience, furigana can be written in either but it is usually written in hiragana. There are a few exceptions that will almost always be written in katakana, but I've only seen one or two words so far that do that.
In other circumstance (not articles, books, papers, etc) katakana may be used. For example, when filling out paperwork in Japan, I've been asked to write out the furigana for my name and address. They requested that the furigana for my name be written in hiragana and my address in katakana (Depending on whether the box said ふりがな or フリガナ). Another situation was in my textbooks or kanji books. When listing The different readings for a kanji, the on-reading is always written in katakana and the kun-reading is always in hiragana.
