The short form of "you will", and occasionally of "you shall" (that second one is old-fashioned and you can ignore it). It is completely normal in speech and in friendly writing — emails to friends, messages, novels. In very formal writing, such as an academic essay or an official report, people usually write "you will" in full.

of "you will"「you will」的 The short form短形式，and occasionally偶爾也是 of "you shall"「you shall」的縮法（that second one第二種 is old-fashioned已經老派，and you can ignore it你可以不管它）。It is completely normal它完全正常，in speech and in friendly writing用在口說和輕鬆的書寫——emails to friends給朋友的信、messages訊息、novels小說。In very formal writing在非常正式的書寫裡，such as像 an academic essay學術文章 or an official report或正式報告，people usually人們通常 write "you will" in full把 "you will" 寫完整。

Two things worth knowing. First, the apostrophe stands for the missing letters w-i, and it is not optional: "youll" is simply wrong. Second, in fast speech it often sounds like just "yull" or even blends into the next word, which is why learners hear a sentence like "You'll be fine" and think a word is missing.

Two things worth knowing有兩件事值得知道。First第一，the apostrophe這個撇號 stands for代表 the missing letters w-i少掉的字母 w-i，and it is not optional而且不能省："youll" is simply wrong直接就是錯的。Second第二，in fast speech在快速的口語裡 it often sounds like just它常常聽起來只像 "yull"，or even blends into the next word甚至和下一個字黏在一起，which is why這就是為什麼 learners學習者 hear a sentence like聽到像 "You'll be fine你不會有事" 這樣的句子，and think a word is missing會以為少了一個字。

Remember that "you" here can be one person or many people, and it can also be the general "you" meaning "anyone": "You'll find the hotel on the left" (you specifically) versus "You'll never know unless you ask" (people in general).

Remember that記得 "you" here這裡的 "you" can be one person or many people可以是一個人或很多人，and it can also be也可以是 the general "you"泛指的 "you"，meaning "anyone"意思是「任何人」："You'll find the hotel on the left旅館就在左手邊"（you specifically專指你）versus對比 "You'll never know unless you ask你不問就永遠不會知道"（people in general泛指大家）。