A question that is free of any grammatical or logcal errors, should be labeled 'yes', otherwise it should be indicated as 'no'. A question is grammatically correct if all its entities i.e. nouns, verbs, adjectives, prepositions, pronouns, adverbs are at appropriate position. A question is logically correct if the semantic makes sense.

Ex Input:
Sentence: Some government officials were concerned that terrorists would take advantage of such breakdowns.
Question: Is it normal for the officials to be concerned?

Ex Output:
No.

Ex Input:
Sentence: Zarco and Teixeira were appointed co-governors of Madeira, while Perestrelo was awarded Porto Santo.
Question: What happened after Perestrelo was awarded Porto Santo?

Ex Output:
Yes.

Ex Input:
Sentence: All Ana had to do was spell this last word and she would be the winner.
Question: How long did it take her to spell the word?

Ex Output:
Yes.