You think it's 6 o'clock, but you aren't sure. What is the best way to ask?
Choose one answer.
a. "It's six 0'clock, isn't it?" (no change in intonation)
b. "It's six 0'clock, isn't it?" (voice goes down at the end)
c. "It's six 0'clock, isn't it?" (voice goes up at the end)