Pinyin Lessons Study Material GoodChinese
[ie] is compound final. The first vowel is pronounced by making the mouth opening narrow and the sound soft and short, and then it glides quickly to the second vowel which is formed by opening the mouth widely and is long and loud.
[üe] also is a compound finals. When you pronounced the first vowel the lips are forced into a round position. Then glides quickly to the second vowel. üe?€change respectively to "yue" in written forms when standing as a syllable alone.
It is a retroflex final. [er] is produced by first half opening the mouth and placing the tongue flat, and then , when "[e]" is made, raising the tongue tip close to the hard palate and putting it down a gain immediately. "er" forms a syllable alone. Sometimes, "er" is combined with another final in the preceding syllable to form a retroflex ending. The Chinese character for "er" is "?? (ér); such as :哪儿.