How is you both singular and plural?
No reason to be snippy Rover_KE. "You" can be singular or plural depending on how it is used. You can think of some examples can't you?
I am really surprised that a retired academic native Engish speaker doesn't know that "thou" used to be used in our language, but has fallen out of favor.
Don't be surprised! If a teacher is talking to a single student, he might say, "Bobby, I want you to go to the board and solve this math problem." Or, the teacher could speak directly to the whole class of 25 students and say, "Okay, now I want you to take out your books." In the first example, "you" is singular:in the second, it is plural.
In most cases there is no ambiguity.
Remember that in informal English there are many alternatives for the second person plural: y'all, youse, yinz
Post sometimes as if sometimes I am a learner, thought it may help those who do not have a command of the English language. We should all be life long learners no one is an absolute English maven.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.