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.

[Q]: Sentence: In Colombia, the drug-financed guerrillas trying to seize the country and destroy democracy include M-19, which Castro has clearly backed. 
Question: How long had the guerillas been supported by Castro?
[A]: Yes.


[Q]: Sentence: She told me that she was heading for a drink and slipped out of the crowd. 
Question: When did she have a drink?
[A]: Yes.


[Q]: Sentence: In Malaysia, Powell met with Prime Minister Mahathir Mohamad, who has led the country since 1981. 
Question: How often does Powell travel to other countries to meet their leaders?
[A]:
Yes.


