left vs leaves

[poorboy_9]

While correcting some finals, a question arose concerning possible answers to a “fill in the blank” question. The initial question asked students to fill in the blank with the proper tense of the verb in the parenthesis. The question read:

“You missed your plane. The flight _______ at 10 o’clock.” (leave)

While most of the students answered in the simple past (left), there were several that answered “leaves”.
To me both answers could be correct. (1) Am I off base?; and (2) To elicit “left” as the only correct answer, should the question have been worded “Your flight ______ at 10 0’clock”?
B.

[svartnik]

While correcting some finals, a question arose concerning possible answers to a “fill in the blank” question. The initial question asked students to fill in the blank with the proper tense of the verb in the parenthesis. The question read:

“You missed your plane. The flight _______ at 10 o’clock.” (leave)

While most of the students answered in the simple past (left), there were several that answered “leaves”.
To me both answers could be correct. (1) Am I off base?; and (2) To elicit “left” as the only correct answer, should the question have been worded “Your flight ______ at 10 0’clock”?
B.

No, you are not off base. I agree with each point you raised.

[poorboy_9]

I also had “had left” as one of the answers. What do you think?

[svartnik]

I also had “had left” as one of the answers. What do you think?

That is possible too with either sentence.

[bhaisahab]

At a pinch I suppose 'leaves' could fit, but not 'had left'.

[poorboy_9]

Bhaisahab, I can see where “leaves” would be correct if you were talking about a daily flight that departs every day at the same time, but agree that “had left” doesn’t fit in the two sentence context.
B.
Thanks for your help!