У меня - I have У тебя - You have У него - He has У неё - She has У нас - We have У вас - They have У них - They have
У вас is said to a group of people who you are talking more directly, у них is said to a person/people when you are talking about someone else, for example you say to your teacher pointing at a group of students 'They have it'
It is indeed, but it's caused by the fact that in Russian you go formal by using plural forms of pronouns that refer to the person you are talking to. For example, "ty" is the proper translation of "you" when you're talking to a colleague, but you should use the plural form "vy" when talking to an adult stranger or somebody who's somehow superior to you.
This manner of switching to formal speech by the use of plural pronouns is not limited to Russian. Here's an article on how it's done in various languages:
Just to note something. Think it is important. In the old days, back here in my country (Serbia) we used to talk like that. Instead of: Ја имам which lierally means I have, we used to say У мене, which meant the same thing like in Russian. It is a less agressive way to say that you HAVE something. It was used with family, friends, even domestic animals, due to respect, but not for things, such as house. Today we use only more agressive way of expressing possession, but Russians kept it in the more broader sense. So when they say У меня есть, that goes for everything. I only wanted to emphasize that У меня есть is a way of expression possession in a more milder way. And it literally means "Inside me".
Mightypotatoes states that у меня is used in that sentence as "by me"; As I understand, у is not referring to I, nor in any way English speakers normally use subjects (menya nor tebya are subjects); rather it indicates possession. Such an example is У тебя есть кошка, where is refers to "By you is a cat" whereas У меня есть кошка is "By me is a cat". The cat here is actually the subject, which is "being". Hope I was helpful.
Я is "I": я такеру = I am Takeru. However, when Russians write out possession, it is different than in English. They write "By I there is X", instead of "I have X". The меня is in the genitive case, a case indicating possession (also note however that "I" is not the subject; the subject is what's being possessed) Thus, У меня есть волк means "By - me - there is a - wolf"
Taken from Duolingo's Basics 2 Notes: English prefers to express ownership and “possession” with the verb “have”. In Russian “existence” is almost universally used instead (in the official/academic style «иметь» to have is OK to use).
Use it like that:
У A есть X ~ by A there is an X → A has an X The owner is in the Genitive case (more on that later) while X is formally the subject. For now we will only study the Genitive form for some pronouns.
You have made repeatedly clear on this and other sentence discussion boards that you think that this site is garbage - you use the word "site," not "app," which makes me think that you are using the actual web version. (The web version has notes; the app versions do not always, to my knowledge. I only ever use the app version after I have already reviewed the lesson on the web version.) Home -> Click on a skill such as "Alphabet" -> Click on the light bulb. I encourage you to scroll around and see what you can find.
NB - Duolingo's notes are helpful but are not all-inclusive. Many of us have also supplemented our learning on Duolingo with other sites such as RussianLessons.net and RussianForEveryone.com, which are able to go further into detail on certain aspects of grammar or usage.
Regarding a Cyrillic keyboard, there are other discussion boards on this topic, so I won't go into it here for brevity. You can also do a google search for instructions specific to your operating system or mobile device. It is all straight-forward.
We as a community welcome honest questions which help to contribute to the overall lessons within the course. If you feel that this site is not meeting your learning needs or uses methods which are not helpful, it is ok - we all learn differently. While I hope that Duolingo helps you reach your goals in learning Russian, you may find other sites or in-person courses at a local university more suited to you. I wish you the best in your learning.
Not really stupid, actually it's the best way to learn a language - by using it. And, you know, there are helpful hints in every task so you're not "magically" supposed to know something, you're just supposed to read them, think and finally find a correct answer, sometimes by trial and error method. No magic here ;)