(1) Are you doing any volunteer work? How about your friends?
1. Yes, I am. They are doing (some) volunteer work, too.
2. No, I'm not. They are not doing (any) volunteer work, either.
(2) Do you do any volunteer work? How about your friends?
1. Yes, I do. They do (some) volunteer work, too.
2. No, I don't. They don't do (any) volunteer work, either.
(Would you check the answers one more time? Do we have to add 'some' or 'any'? Or Do we not need to use 'some' or' any' when we answer the questions?)
All are really good. You can either use "some" or "any" or not, as you wish.
Nice! =)
When answering the questions about volunteer work, you have a couple of options.
For question (1), you can answer:
1. Yes, I am doing volunteer work. They are also doing volunteer work.
2. No, I am not doing volunteer work. They are not doing volunteer work either.
In these sentences, you don't need to use "some" or "any" because you are simply stating whether you or your friends are involved in volunteer work or not.
For question (2), you can answer:
1. Yes, I do volunteer work. They also do volunteer work.
2. No, I don't do volunteer work. They don't do volunteer work either.
Similarly, in these sentences, you don't need to use "some" or "any" as you are just stating whether you or your friends are engaged in volunteer work or not.
So, in summary, you don't need to use "some" or "any" when answering these questions about volunteer work, unless you want to emphasize the quantity or degree of volunteer work being done.