Let us learn japanese Part 2

Katakana Function

For Writing

1. words derived from foreign languages (Foreign names of people and places and foreign objects).
2. names of animals and plants
3. word imitating a sound
4. words to be emphasized (capslock word)
5. telegram

besides writing katakana foreign word can also be used to write the original Japanese language so the speech was appropriate based on the sound system of the Japanese language there are many katakana which can be used directly as part of the kanji

how to write a word derived from foreign languages

• Katakana (片仮名?) are used to write the following:

transliteration of foreign words and names, such as コンピュータ (konpyūta, "computer") and ロンドン (Rondon, "London"). (Some foreign borrowings that have become naturalized may not be rendered in katakana.) See also Transcription into Japanese.
commonly used names of animals and plants, such as トカゲ (tokage, "lizard") and バラ (bara, "rose"), and certain other technical and scientific terms, such as mineral names
occasionally, the names of miscellaneous other objects whose kanji are rare, such as ローソク (rōsoku, "candle")
onomatopoeia, such as ワンワン (wan-wan, "woof-woof"), and other sound symbolism
emphasis, much like italicisation in European languages.
Katakana can also be used to impart the idea that words are spoken in a foreign or otherwise unusual accent; for example, the speech of a robot.