TASK DEFINITION: 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.
PROBLEM: Sentence: Sarawak's coast and jungle interior were controlled by the Iban — Sea Dayak pirates and Land Dayak slash-and-burn farmers. 
Question: How long did it take for the Iban to take control of Sarawak's coast?

SOLUTION: Yes.

PROBLEM: Sentence: Our investigation has uncovered no credible evidence that any person in the United States gave the hijackers substantial financial assistance. 
Question: What happens after the hijackers are caught?

SOLUTION: Yes.

PROBLEM: Sentence: They first traveled by plane around Europe, where they saw many different people and sights. 
Question: What time did they normally board the flights?

SOLUTION:
Yes.

