or vs. and ( I have no brothers and/or sisters.)

[Sweetpumpkin]

Hi,

I have some questions on 'or' and 'and'.

1) I have no brothers and sisters.
2) I have no brothers or sisters.

In this case, I think 2) is more natural. But how about 1)? Do you think it's wrong? If so, why? Please let me know.

Thank you in advance,
sweetpumpkin

[Nyc]

This whole forum is more about logic than linguistics, isn't it?

In everyday conversation, I suppose there is no difference between 1 and 2. Logically, though, they are very different and can be used to mean opposite things.