"He has not got a mother."
Thanks for that...
Any reason why? Does what I said simply make no sense, or does it mean something different? Putting my sentence into Google translate gives me 'He is not a nut'!
Your translation is ungrammatical. You need to use "keine".
"Kein is used in a sentence when the noun to be negated has an indefinite article."
PS: Don't use Google Translate. "He is not a nut" is complete bs.