When writing/speaking Japanese, how do I know when to use each of the scripts (kanji/kana)?

Question:
I know that katakana is only used for foreign names and words, and to put emphasis on certain words or phrases (like italics is in English.) But how do I know when to use kanji and when to use hiragana? Do I only use hiragana if there's not a kanji symbol for that word, and otherwise use kanji as much as possible?

Answers:

Answer by Bostezo
You're pretty much dead-on. If there is kanji for a word, it's generally advisable that you use it instead of hiragana.

There are some exceptions, however. There are often rarely-used Kanji for foreign place names (Such as ?????for "America"), but using Katakana for these place names is more common ("????")

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