Sorry for clearing the board off I thought you were done. Correction: I'm sorry for clearing off the board. I thought you were done/finished. Other practice to do today. Correction: I have to practice today. I have more work to do. If someone is asking you if you want to hang out with them and you want to say "no" as a refusal, just say: I'm sorry, I have work to do. Maybe we can hang out another time. I refuse that opinion. Correction: "I refuse that opinion" could sound rude to someone you don't know or like, so a more polite way is to say, "I disagree with your opinion." That way they know that you believe something differently, without coming off as offensive or irritated. I you must get the book back(.= give back ?) Correction: I must give the book back to you. Can I give the book back to you? When can I give you the book? Do you want/need the book back? What's the price to go to...? Correction: What is the price? Is the price changing? What price will it go to/change to on that day? Any corrections pending? Are there exercises pending correction ? Correction: Do I have any mistakes? Does anything need corrected? Do I have any corrections? Are there exercises pending correction? I hope these help you. :)

Hmm, let me see... 1. The sentence is correct, I would just add a comma after "off" for a pause in the sentence. 2. Instead of starting the sentence with "other" you would start the sentence with "I" because you have other practice to do. You could also change "other" to "another" to make the sentence make more sense. 3. In English, most people say "I disagree with your opinion" instead of "I refuse your opinion". I can understand the sentence, though! 4. You can use I/you for the 4th sentence, but don't use both of them in the same sentence because that will confuse people on who you're talking to. 5. Instead of "What's the price to go to" you would say "What's the price for this?" if you're asking how much is. I hope this helped a little! I'm not used to helping people learn English. Good luck on your studies!