Afrikaans has mostly lost grammatical gender in its article system.
That means:
So die is the expected article here.
This is a classic false friend for English speakers.
In Afrikaans:
In English:
So although the spelling is the same, the meaning is different.
Because it comes after is, where it functions as a predicate adjective.
In Afrikaans, adjectives in that position usually stay in their basic form:
So warm stays warm here.
For a yes/no question, you usually move the verb to the front:
That is a very common Afrikaans pattern:
Standard Afrikaans usually uses a double nie pattern:
So you will often see:
This double negative is normal in Afrikaans grammar.