***** Practical recommendation: If you are not totally familiar with Japanese, you should not use the word "おかしい" to describe "funny" things. It is socially safer for you. >but does 面白い mean something positive, while おかしい means something negative? You are right basically and etymologically. ***** Etymological reason. おかしい came from the noun "をこ”, which meant "silly" And now it means "wrong", "strange", "out of order", which leads to "(silly/crazy and) funny". This means "おかしい“ always has a slight touch of meaning "silly/wrong/weird". It is not safe for you to use this word to describe other persons except for comedians whose business is to play silly to get people's laugh. The word おもしろい originally meant "Bright around here", that turned to mean "beautiful, splendid, interesting", and now it means "interesting, amusing, funny(= making someone have fun)". That's why : OK: 日本語の勉強はおもしろい OK: 日本語の勉強は楽しい OK: 日本語の勉強は興味深い NG: 日本語の勉強はおかしい

面白い; funny, interesting or exciting. おかしい; funny, wrong or strange. For example, if you watch funny TV show or your friend tell a joke, you can use both words. However, if someone tell a joke in formal speech, you should use 面白い.

.. ＜＜　おかしい　＞＞ １．Funny (LOL), ridiculous, comical (laughter-inducing) The meaning is closer to LOL than to "amusing." Can be written with kanji 可笑しい but only in this sense no. 1. 可笑しいジョーク　(funny jokes) 彼のおかしい身振り (his funny gestures) 何がそう可笑しいの？ (What's so funny?) 2. weird, strange, odd, unusual エンジンの調子がおかしい。 (The engine's condition is strange.) おかしい、鍵が見つからない。(Strange, I can't find the keys.) 六月に雪が降るのは、おかしい。(It's odd to have snow in June.) その男の様子は、最初からおかしかった。(The man's behavior was odd from the beginning.) 3. inconsistent, illogical, unreasonable, not making sense その議論はおかしい。(That argument is illogical. ) 君の話はおかしい。 (What you're saying doesn't make sense.) ＜＜　面白い　＞＞ 1. funny, amusing. Same as 「おかしい、可笑しい、meaning no. 1 」but the meaning is closer to "amusing" than to "LOL." 面白いジョーク　(funny jokes) 面白い先生 (an amusing/entertaining teacher) 2. pleasant, enjoyable, delightful コンサートは面白かった。(The concert was fun.) 日本語の勉強は面白い。(Studying Japanese is enjoyable.) 3. interesting, intriguing, fascinating 面白い計画　(an interesting project) 彼は面白い金儲けの話を持ってきた。 (He brought me an intriguing money-making deal.) .