2. "Yu", as a preposition, is a function word used more frequently in ancient Chinese.
"Yu" is not a simplified word of "Yu" (neither the Summary of Simplified Chinese Characters nor the General Standard Chinese Characters List stipulates that "Yu" is simplified to "Yu", and the Xinhua Dictionary has the same interpretation of "Yu").
"Yu" and "Yu" are similar in most cases, but "Yu" cannot replace the full meaning of "Yu".
Yu is also a surname, which is different from surname.
There are three pronunciations of the word "Yu", namely, yú (Yu), wū (Yu) and yū (pedantic);
Although "Yu" is generally abbreviated as "Yu", when the word "Yu" has two pronunciations: wū (blare) and yū (pedantic), it cannot be abbreviated as "Yu", such as "Yu", "Yu Tu" and "Fan" in pre-Qin literature.
In general, "Yu" can be used through "Yu", but it also has some special and unique meanings, such as taking "Yu" as the surname and taking "Yellow Bird in the Air" and "Feng Huang Yu Fei" as the verb prefix, instead of "Yu".