"Cannot" or "can not" ?

[Emi_languages]

Hello,

I am wondering, which version is correct - "Can not" or "Cannot" ?

I always thought this modal verb with the negative particle "not" should

be written as one.

Is there any grammatical rule as to that?

e.g. "It can not be named (...)"

Thank you in advance for all your ideas! :-)

[Gerardd88]

Teoretycznie obie formy są dopuszczalne (źródło). Mimo to cannot jest nieporównywalnie częściej używane.