I wasn't sure whether you were asking about the grammar, or whether you wanted an actual answer! If you wanted some sample answers, then Dan has given you some nice ones above. His reply also points up some differences between British and American English. Our tense use is the same, but the adverbial phrase about the weekend is different. What are you doing at the weekend? (GB) What are you doing this weekend (US/GB) What do you do at the weekends? What do you do on weekends? (US/GB) And, if you are interested, this is one of the few cases where Australians and New Zealanders follow the American rather than the British usage. If anyone would like to correct me on this, or add to it, please comment!

"What are you doing this weekend? If you are not busy, would you like to some visit us?" "We don't have anything planned for the weekend, we'd love to visit, thank you." --- "What do you do on weekends?" "During the summer, we like to go hiking at Blue Hills Reservation."

Sorry, I've just realised that I got my explanatory brackets wrong. I should have written: What are you doing at the weekend? (GB) What are you doing this weekend? (US/GB) What do you do at the weekends/ at weekends? (GB) What do you do on weekends? (US)

Thank you very much agian ! You answered what I wanted .

Do you mean "What do you do at the weekends?" or "What are you doing at the weekend?" . The first is asking in general about every weekend, while the second is asking about your plans for this weekend. If you mean the first question, then you need to use the present simple 'What do you do..?'