VIetnam was ruled by China until the middle of the 10th century. So many Chinese words entered the language that Vietnamese was long thought to be related to Chinese. It was written using the Chinese characters until the 17th century, when Catholic missionaries devised a Roman-based orthography. It contains a complex system of diacritical marks, some distinguishing certain vowel sounds, others indicating tone. As can be seen in some of the lines above, a letter may often contain two diacritical marks.
The Tale of Kieu, the Vietnamese national poem, was written by Nguyen Du in the early 19th century. It is 3,254 lines in length； educated Vietnamese know most of them by heart.
责任编辑：刘小蜗
