The Russian word for “yes” is “да” (da). If your answer is “Да”, you can also say, “Хорошо!” (Horosho!). You can give an affirmative answer by using an informal exclamation “yep” which means “da” as well. The word “yeah” is related to vernacular. It also means “da”. The particle “da” can have the meaning “let” or “may”. So when you say, “Да будет так” (Da budet tak), you mean “So be it!”