Because this is a simple main clause with a subject, a form of to be, and a description:
So the structure is:
Subject + verb + complement
That is very similar to English:
This is a very common learner question.
In Afrikaans, adjectives often take -e when they come before a noun:
But when the adjective comes after a linking verb like is, it usually stays in the basic form:
So:
A rough English-friendly guide is:
oorwinning ≈ OAR-vin-ning
A few notes:
The stress is typically near the beginning: OOR-winning.
A rough guide is:
ongelooflik ≈ on-khuh-LOAF-lik or on-ghuh-LOAF-lik
Helpful notes:
If you cannot yet make the Afrikaans g, learners are usually understood if they use a softer sound at first.
You would use the indefinite article 'n instead of die:
'n Oorwinning is ongelooflik.
That means A victory is incredible.
A useful detail:
So you would write:
not: