These words are homonyms . Есть means there are/i have/ etc. And it means to eat as well. In English there is the word Well which corresponds to good ,and has a meaning of water/oil source. You can find key in your pocket and in a piano...and so on. To trouble you a little bit more, есть! means yes,sir!)))
In Russian the old information usually goes first and the new information goes last. So if we are talking about a certain plan (hence "the plan" in English), we put it in the first part of the sentence. More about that here: https://www.duolingo.com/comment/13955228
Also the "есть" word, which is not as optionall as it might seem. It is used when the existence of something is questioned. "Is there a plan by you?" is a clumsy but more accurate translation of "у тебя есть план?". While in "do you have the plan" the existence of the plan is not questioned. We know it exists, and we are inquiring whether or not that person has it. So "есть" is not used.
i wrote "u tebya est plan" and it was a mistake. i dont see the mistake here! can someone explain? :)
I am from Croatia and a lot of Russian words connect with ours. So I have a question; Doesn't it ("У тебя есть план") mean something more like "Do you have the plan at your possesion?" than just asking if the person has come up with a plan? Because the first option is much more similar and logic due to grammar.
I see you've studied some German. Russian, like German, has a case system, meaning that nouns change according to their syntactical meaning in the sentence. Тебя is the genitive case equivalent nominative word, ты, you. Modern English does not have a case system, so 'you' in English can mean the subject of the sentence, the object of a preposition, an indirect object, etc. Тебя, as in ,,у тебя план,, 'you' set in the genitive case. Next to the preposition ,,у,, it becomes 'with you'. Тебе means ''to you''.