"Where is the signature?"
Translation:Gdzie jest podpis?
That would mean "sign the signature" which doesn't make sense to me, because you usually sign a document or a letter but not the signature itself:
- Podpisz dokument.
- Podpisz list.
- Podpisz pocztówkę.
If you want to use the noun "signature", it must take the instrumental case, which denotes the means of an action:
- Podpisz podpisem = sign with a signature.
Although grammatically and semantically correct, this sentence by itself is a total pleonasm, because the noun is completely redundant. It's only really permissible to use this construction if you're talking about a specific type of signature, so there's a good reason it needs to be mentioned twice:
- Podpisz podpisem kwalifikowanym - Sign with a secure digital signature.