four tones

基本解释

Its vowels include plain, pharyngealised, strident and breathy, and they carry four tones.
元音包括簡單音，咽音，刺耳音，氣音，而且有四個聲調。
The "slowest" language, Mandarin, partly thanks to the four tones, has around 2000 possible syllables, far more than Japanese or Spanish.
語速最慢的漢語普通話有大約2000個音節，比日語和西班牙語多得多。有四個音調也是普通話語速慢的部分原因。
Not only do foreigners find it difficult to master the four tones of Mandarin, but the alien grammar and the difficulty of rote-learning thousands of words overcome all but the most diligent students.
外國人不但覺得漢語中的四聲調很難掌握，而且那些陌生的語法和死記硬背的成千上萬的漢字也讓他們頭疼，似乎衹有最勤奮的學生才學得會。

Then students have the daunting task of learning to pronounce Mandarin, where one word can have four meanings, depending on which of four tones is used.
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