TIL: The hyphens over Chinese vowels, when written using the Latin alphabet, describes how to properly pronounce the vowels in Chinese. Eg. à goes from high tonality to low

https://en.wikipedia.org/wiki/Pinyin

https://www.reddit.com/r/todayilearned/comments/15ian9o/til_the_hyphens_over_chinese_vowels_when_written/