2nd vs 3rd person

[christ0fr]

This is a very basic question, but my English brain has a hard time distinguishing between second person plural and third person plural. I know second person plural is for example: "You (guys) are from Spain" which would be "(Vosotros) sois de España" in Spain or "Ustedes son de España" in Mexico for example. For third person, it would be: "The kids are from Spain" which is "Los niños son de España." However, I came across this sentence which I *think* should be second person plural, but not really sure: "You (tú) and the children are from Spain." In Spain, would you say "Tú y los niños sois de España" or "Tú y los niños son de España" ? That is, is "tú y los niños" second person plural or third person plural? 

Thanks!

[JFellow]

I agree with your own assessment.

In English I can say, What sayest thou? This is purely second person singular. Or I could say, What sayest thou, and what say the rest of you? In this case I simply have added a plural second person to the original singular second person. Or I could simply say, How are ya'll? I mean how art thou, and the kids? Second person and more than one so plural. Also he/she is simply stating a fact of being (where they are from), which applies to them all.