Below are some pieces of advice for learning Japanese in earnest.

Intermediate

  1. Learn only the most relevant reading of a kanji. You don't have to know all of the readings. Which reading to know depends on your level
    One of the best ways to learn the appropriate reading is to learn these in the right context for your level. For example, the kanji byo as in byooin (hospital) has another reading, yamai, but this reading may not be of any use until you reach a more advanced level.
    The knowledge that kanji can be classified into six major categories - rikusho - will help you learn them better.
  2. Make sure that you can construct complex sentences with so-called adjective clauses. For example, Yamada san ga kinoo yonda hon wa watashi ga 1-chinen mae ni yonda hon desu. (The book that Mr Yamada read yesterday was the book that I had read a year ago.)

  3. Distinguish intransitive verbs from transitive verbs that have similar meaning. For example, otosu means 'to drop' as in You dropped a pen on the floor., but ochiru means 'to drop' as in Your pen dropped on to the floor a few minutes ago.

  4. The Japanese are passive in expressing their sentiments. When one talks about his/her ability; for example, the ability to remembering so many kanji (Chinese characters), one can say this in at least two different constructions.

    (1) I have the ability to remember a lot of kanji.
    (2) Some unknown forces enable me to remember a lot of kanji.

    The subject of the construction (1) is the agent- “I” who actively makes the effort and achieves the target of remember kanji.
    In this construction the agent is seen as active and contributes to the outcome. This results in an English sentence such as “I can remember so many kanji!”
    However, this is not what Japanese people do. Japanese prefer (2) construction in which they seem to be saying that “I am made capable of learning so many kanji.” Or “I do not do any active effort on my own, but some unknown outside force caused me to learn what looks impossible.”
    This result in “Takusan kanji ga oboerareru!”（「たくさん漢字がおぼえられる。」）

    Notice when a Japanese person achieved a remarkable outcome, they often say “Okagesama de”（「おかげさまで。」）, which literally means “ Your caring shadow made me achieve this!”