Go to https://lexlatin.com/ and there you will find your answer.
I’m not sure what you mean by affirmative but when adding pagar to a sentence that uses “ustedes” it would then become PAGAN.
1. correct
2. Correct
3. Correct
4. Wrong — Te acuestas
5.Correct
6. Correct
7. Correct
8. Correct
9. Correct
10. Correct
GOOD JOB
This sentence is grammatically INCORRECT.
It's supposed to be Gerardo te <span>compra la cena.</span>
I would think D) nos relajamos because nosotros is plural and means we. And nosotros used -amos or -imos.