Short short with English summary                         

日本語は、雪やこんこん ざーと大雨 といった、オノマトペ「onomatopoeia」・ 擬音が多いので有名だ。「シュッシュポッポ」「ガタンゴトン」といった直接的擬音は、判りやすく、外国人でもチョット努力し練習すれば使いこなせるようになる。だが、日本語には、「うんと チョット やっと ほっと ほんの まあ まあまあ じたばた ざっくばらん あやふや ごたごた ばらばら やれやれ ぞろぞろ ・・・」といった、単語(副詞・形容詞)と擬音の中間語が実は大変多く、しばしば舌上にのぼる。会話上のみならず、たとえば、松本清張の小説を検証的に精読すれば気が付くことだが。読みやすい文章には、ほどほど、上手に入れられている。 この会話語とも呼ぶべき半擬音を使いこなす外人は、日本語がうまいとされる。

A language with power of message
Japanese, as a language, is known as full of onomatopoeia. “Shushu popo (loco train)” and “Gatan goton (train on rails)” are directly from their sound. Foreign learners could easily master them. Meanwhile there are many words having character of something between onomatopoeia and common words: “unto (much)”, ”chotto (slightly)”, ”yatto (finally)”, and many others as ”hotto”, ”honno”, ”maa”, ”ayahuya”, ”gotagota”, ”zorozoro”… These words turn up often in daily conversations and literal sentences. The foreigners who can use and handle those words are considered good in Japanese.
Are there the same sort of phenomena in other languages?
In Indo-European language group, their letters are phonetic; therefore, often the words are rather onomatopoeic such as shower, slash, hit, click and knock. In English daily conversation, we hear quite often extremely obscene ones; shit, piss, fuck and sonofbitch or religious ones; Jesus, Maria, Christ, My God and Hell. The Chinese situation, having only characters, are interesting but I do not know.
Japanese is a very difficult language. Chinese characters, two phonetic kana letters, borrowed words from foreign languages, further more honorifics and socially structured stiff language system; there are many aspects causing difficulty. However, you can manage them through your effort. Furthermore, to be a good Japanese-speaking person, a Japanese or a foreigner, you have to master Japanese onomatopoeia through daily conscientious training in a good chatting companion.