Why isn't this "I did not see you all month"?
Good question. Some verbs they want you to use "did", others "have", otherwise you get it wrong.
The pretérito perfeito in Portuguese translates as simple past and present perfect - depending on context. In this sentence, the present perfect is the preferred tense, and the simple past would be acceptable.
Oy vey, this is confusing. Just before it was "o dia todo" now it is "o todo mês" o.O Does it matter at all where "todo" is placed?
Yeah, I wasn't sure if todo refered to você or o mês ...
I've put 'I have not seen you the whole month.' Is it right?
It's okay, but "all month" is more usual.