The word you is a combination of two words, yore and the “m” or “mood” letter, which have different meanings. While yore is a quaint old-fashioned word for the past, the “m” is a contraction for the word “your”, a definite noun, which sounds like you. However, yore is not a commonly used word in modern English.
You and your are both cognates of Dutch jij and je. They are also cognates of Low German jug and euch, and have the same eow syllable as iow. Your and yore have an overlap in 16th century usage, but the nouns are still different.
You and yore are both excellent examples of the word for that. Their use is mainly informal, but yore is sometimes used for the same reasons. And if you want to sound fancy, you can use the contraction “you’re” to substitute for your. It’s not always easy to know which is which, but a little apostrophe will make the difference.
The simplest way to think about you is as a second-person personal pronoun. In Modern English, you functions as a dative form, and is used before nouns. Until the 18th century, you was only used for singular cases. This changed in the 18th century, when you lost respectability and became more commonly used as a subject pronoun. Today, you is used for both singular and plural cases, and can be the subject of a verb.
There are many other forms of you, such as y’all and you-all, but the word you stands out. You-all is a tense that is most common in the South Midlands of England and Ireland, and the contraction you-all is used for all numbers, though you is not a word commonly heard in American vernacular.
You-all is also a useful construction for non-native speakers. However, it is rare in educated speech, and its uses range from formal to casual. Depending on the person you ask, the question might be a subtle one, or a more direct one, such as, “Would you like to talk about X?”
The most important thing to remember about you is that it’s a second-person plural personal pronoun. That is, it triggers a plural verb agreement. Generally, this is not a problem, but the gendered language of today can be problematic for trans and genderqueer people. Luckily, this is a change in the wind, and most of us are probably more likely to perceive it than we would have been in the past. Fortunately, you is one of the more familiar pronouns, so after a few hearings, you should be able to pick up its nuances. But be aware that you will have to learn some new words in the process!
The word you might be the most important word in your vocabulary, but you’ll need to learn a few more. One of the other major words of the same name is yow, which is a nominative form of jo and iow.