Many people think that Learning to speak Japanese language is more difficult than learning to write Japanese. But, it is actually vice versa, because there are 3 different Japanese symbol called Kanji, Hiragana and Katakana, if you want to learn to write Japanese.
Normally, many Westerners think that kanji symbol is the only writing form we use in Japanese. It is true that we use kanji symbols more than hiragana or katakana symbols when writing something in Japanese. However, unlike Chinese people who use only Kanji symbols, we mix up all Japanese scripts.
So, when do you have to use which script? The answer is it all depends on a type of sentence used. Generally, the majority of Japanese textbooks says that Hiragana symbol is used when a word cannot be written in Kanji symbol, and Katakana symbol is mainly used to represent foreign words, or names which have adopted into the Japanese writing system.
However, it is always the case.
For example, "Thank you" in Japanese is "A Ri Ga To U". Normally, you will write this word in Hiragana symbol, but in a formal letter, you should use Kanji symbol. Although it is not wrong to use katakana symbol to write "Thank you" in Japanese, not many Japanese people would do so.
If you travel to Japan, you would see how each Japanese Kanji Symbols, Hiragana and Katakana symbols are used
For example, Japanese Magazine normally use 80% of Kanji symbols, and 10% of Hiragana and Katakana symbols.
Another case is the singboard of the place in a subway. Almost all the sings are written with the Kanji symbols. By the way, we can write numbers in kanji symbols as well, but normally use the numerical sign to represent.
Also, Japanese language is changing everyday. There are new Japanese words in which old Japanese people cannot understand and those words are usually written by Katakana symbol or Hiragana symbol.
Although they are not proper Japanese language, many young Japanese people use such characters nowadays, and those words are normally abbreviated words.
That is why leaning to write Japanese is more difficult than speaking Japanese.