We would like to go to Spain this year as both kids (10 and13) doing Spanish at school. Which parts are best for this (signs, general conversation etc) as the Spanish they learn in school is not the Spanish apparently they speak in the south of Spain! Neither my husband or I have been before or speak Spanish as you may tell! We would like to have a nice beach for a bit of snorkelling and somewhere with things to do. Any ideas?
Don't know about the snorkelling but lived in Spain for 8 years.
Assume they are learning standard Spanish (Castellano), as opposed to Galician, Basque or Catalan. If that's the case you are safe in southern Spain, though they do drop the s in Andalucía - a bit like Cockney Spanish! Madrid is supposedly where the purest Spanish is spoken but there won't be any snorkelling there. This site might help snorkelguru.com/snorkeling-in-spain/snorkel-spain.htm Hope you have a great time and find the right spot.
Reasonable snorkelling off the Costa Brava but they speak Catalan there and although they would speak Castilian to you, I suspect they might prefer to speak English! Andalucian accent is a bit hard to understand due to speed and the dropping of the S, but they will of course understand you if you speak Castilian to them. Costa Blanca has a dialect I think but again they would speak Castilian Spanish to you if you spoke it to them.
Similarly Balearics have dialects like Catalan but will speak Castilian in response to you.
TBH you don't go to Spain for the snorkelling. It's just not that great. Islas Medes in Costa Brava were best but not overly exciting.