Because after a verb like is, bly, or word, Afrikaans normally uses the basic adjective form:
The form positiewe is usually used before a noun:
So in Sy bly positief, positief is the correct form.
Yes. Both are good translations.
The Afrikaans sentence can match either one, depending on context.
In a simple yes/no question, Afrikaans usually puts the verb first and the subject after it.
So: