Quotation Marks - Losing my mind over Excel error

Hello everyone, 

As per title: trying to follow basic instructions (=C4," ",B4) and so on. Excel keeps returning an error message. I am aware of the difference between straight quotation marks and curly, dialogue ones, but still.
As soon as I enter those, error keeps popping up. Please see below. 

 My Excel is set in Italian, is that a location thing? Thank you.