What do the special symbols that sometimes appear on French vowels stand for?

The closed stress Gu: "é" is only used on the letter E and pronounced as [e].

The opening notes are accented: "à", "è" and "á"

For example: 1) The preposition "à" means "zai ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2) "e" [? ], different from "é"

3) Is the conjunction ou "or" different from the interrogative pronoun o? "Where is it?"

Long note stress circle flexe: "?" 、"ê"、"?" 、"?" 、"?"

For example, in modern French, long notes have basically no substantive significance in changing pronunciation (the French speak so fast that they can hardly hear the difference), but they also have the function of distinguishing words with the same writing, such as: sur preposition, above……； ...; And s? R of course, of course (some local dialects are still different)

Hyaluronic acid: "What?" 、"?" , added to vowels e, I, u, indicating that it should be pronounced separately from the previous vowel, such as na? f[naif]]

For example, the word mais means "but". Is that what ma wrote? S means "corn" and is distinguished by extra notes.

Soft voice Sedir: "?" , added to the letter C before A, O, U, indicating that [s] should be pronounced, such as: fa? Ade, France? Open, re? u]

For example, the word "commencer" is pronounced as [S] in the second c, but after the verb is shifted, the first person plural is commencons. According to the pronunciation rules, this C should be pronounced [K]. In order to keep the original [S] sound, a soft note is added under C to make it "commen"? ons .