Act as, be recognized as: take ~. Recognize ~. Learn from it ~ often.

◎ become: become ~.

◎ Yes: twelve taels a catty.

◎ Governance, handling: ~ politics.

◎ Be: ~ The world laughs.

◎ means to emphasize: big ~ annoying.

◎ Auxiliary words, expressing backchat or exclamation: How can we go home if the enemy is not destroyed?

Last name.

* * * * The above is the explanation of "Wei" in Xinhua Dictionary. The following is the explanation of "yes" in the dictionary. *****

He is a worker. The author of The True Story of Ah Q ~ Lu Xun.

◎ indicates existence: sweating all over.

It means to admit what you said, and then turn to the correct meaning, which means "although": poetry ~ good poetry is too long.

When you come.

◎ means any: any ~. ~ He is willing to do any job.

Used in question: Has he left?

The emphasis means "really" and "really": the weather is cold.

◎ Yes, reasonable, as opposed to "non": ~ non. He said ~. Seek truth from facts.

◎ You are right: ~ Ancient times are not today. Go your own way. Deep ~ its words.

Express acceptance or agreement (just say "yes"): ~, I'll go.

◎ This, this: ~ days. ~ can endure, can't endure. Everywhere ~.

◎ auxiliary words, indicating the target in advance, only do this: only you ask. Only profit ~ figure.

Last name.

It can be seen that "Wei" is not "Yes" in our traditional sense. What you don't understand is the first explanation of "yes" and the fourth explanation of "for". Although the word "Wei" can be semantically understood as "Yes", the difference between the word "Wei" and the word "Yes" is that "Yes" means to judge, define and classify. He's my family, and he's going 50 miles an hour. In the example, "he" and "speed" have countless possibilities before they are defined. Only after they are defined, the possibility of the former is limited, thus becoming the only possibility without any ambiguity.

And "for" means "yes", which is equivalent. For example, twelve ounces is a catty, which is divided into two. At this time, "Wei" means that the former is the latter, and the former is unrestricted and will not change. Twelve ounces is a catty, and one in the middle is two, which is called meaningless judgment verb grammatically. (Note that the verb in "one divides into two" is "fen"; "Wei" has no practical significance.

In your example, the speed is infinite, which can be 40 or 50. You can only define it by "yes". You can't use "for"