Thanks a lot for the money. I ______ you back next week.

It's great to hear that you received some money! In Russian, the correct phrase to use in this situation would be: "Спасибо большое за деньги. Я верну тебе их на следующей неделе." This translates to: "Thank you very much for the money. I will pay you back next week." Feel free to practice this phrase for your conversation. If you have any more questions or need further assistance with Russian language or any other academic topics, feel free to ask!