I'm not into Japanese but as far as I know, most Hiragana has round curves and Katakana has straight lines. http://www.sf.airnet.ne.jp/ts/japanese/shape_k.html Here's a comparison. As for usage, wikipedia states that Katakana is used for loanwords, (Such as televsion --> テレビ) country names, (Such as the USA --> アメリカ) and company names. (Like Suzuki --> スズキ) source: http://en.wikipedia.org/wiki/Katakana I'm not totally sure about this but as far as I know kids first learn Hiragana, then Katakana and Kanji. Hopefully someone else with more knowledge about this matter can give more information. Good luck!

It is basically the same though there is a thing used properly by the nuance. The image is a difference like writing the alphabet by either the capital letter or the small letter. KANJI that became an origin is different though it was made based on KANJI HIRAGANA and KATAKANA when saying from a literary viewpoint. Origin →http://www.hana300.com/aakana.html →http://meiko.web.infoseek.co.jp/kana/katakana.htm The KATAKAN･HIRAGANA Roman alphabet mark can be confirmed at a time. →http://www.ivysoho.net/mojimoji/kidsb.htm

Yeah, Katakana is used for loanwords, imitative words, the names of animals＆vegetation. For example, the Japanese say like マクドナルド(makudonarudo) when they say 'Mcdonald'. Many signboards in Japan are written in Katakana. So you can automatically be quick in picking up the words if you live in Japan. You can also use Katakana when you emphasize what you write. For example, 愛(あい）してる means 'I love you'. It can be written like 'アイしてる', if the writer wants to emphasize. The pronunciations are the same and It would be lucky for you. Hiragana is from Chinese characters(These were in the cursive style.) of 萬葉集, which is a kind of anthology in the eight centry. In 平安時代(Heian period) Girls at the court had wrote a diary, poems, novels in Hiragana. It stimulated the usage of Hiragana. Most Japanese men used Kanji at that time, so Hiragana was called '女手'(onnade), this means 'Characters of Girls'. At present, Hiragana is a main character the Japanese use. All Kanjis have Hiraganas. So I can subtitute the Kanji for the Hiraganas when I can't remember some Hiraganas. Katagana is from Chinese characters too. Japanese Buddhist monks omitted some strokes of Chinese characters and added parts of speech＆the endings of words. Their various stanography system had brought Katagana's development. At present, Hiragana is a main character in Japanese. Let me know if some Japaneses get me wrong.

Both Hiragana and Katakana are from Chinese traditional character.But now most of Katakana are used for foreign words(especially from the western languages,i.e: English, Deutsch,etc.); But Hiragana mostly ,they are traditional Japanese characters,and Kanji-related characters. Hiragana are just like Rome Roman characters,while Katakana is just like their own languages. Hope the answer have something to you!