Hindi: जब तक...तब तक + नहीं

How would you translate this sentence?

जब तक तुम काम ख्तम नहीं करते हो तब तक मैं यहा बैठी रहूगी।

"Until you finish the work, I shall remain sitting here."

Hindi word reference: जब तक, तब तक, नहीं 

Hindi: merii baat kaa buraa mat manaanaa

In the statement "<erii baat kaa buraa nahiiN manaanaa", can we replace "mat" with "nahiiN" in Hindi?

Yes, in Hindi mat मत and nahiiN नहीं are same.

word reference: merii baat kaa buraa mat manaanaa, मत, नहीं