a o e i u ü are six basic vowels in Chinese language. They are called shēng mǔ (声母 the Initials) in Chinese Pinyin.
To speak a accurate and fluent Mandarin, it is important to pronounce Initials in the right way.
A certified teacher with 20 years of experience teaching Mandarin will show you how to get it right. You can also speak Chinese like a native.
Join our Pinyin Course program to start your journey in Chinese: https://faithchina.com/product/pinyin-training/