Hi everyone,
If I’m referring to a single person, is it correct to say "Do you do all the cooking and washing yourselves? Wouldn’t it be correct to use “yourself” instead?
Thanks in advance. Cheerio
If you are speaking about one person, then ‘yourself’ would be correct.
If you are speaking to one person about, for example, the actions of that person and his wife, then ‘yourselves’ would be correct.
Great. So I’ve found another mistake in an English book for Italian learners. Fortunately I’ve found this wonderful site. 
See you very soon.