"How many languages does your generation speak?"
Translation:Thế hệ của các bạn nói bao nhiêu thứ tiếng?
Grammar notes in this sentence: 1. 'how many' can be translated as 'mấy' or 'bao nhiêu'. 'mấy' is used when the quantity is less than 10. 'bao nhiêu' is used when the quantity is more than 10. e.g.: when you ask how many kids your friend has: Bạn có mấy con?. When you ask how many books your friend has: Bạn có bao nhiêu quyển sách? (assume that she/he is a voracious reader). 2. 'Thứ tiếng' is used correctly here. 'ngôn ngữ' can be used in this sentence as well, 'ngôn ngữ' sounds more nature to me.
Just my two cents.
It is a plural indicator for "you/your" but usually we don't use "các" to indicate a plural "you". Will fix this sentence.
In translating from the given English to Vietnamese, there is nothing to require "các" because "your" in English can be understood as singular.