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.
One example: Sentence: Jack played basketball after school, after which he was very tired. 
Question: How long did Jack play basketball?
Solution is here: Yes.
Explanation: All entities are in appropriate position and the question makes sense, so its grammatically and logically correct.

Now, solve this: Sentence: A thwarted Mongol invasion in 1274 weakened the Kamakura regime. 
Question: Is the invasion still taking place today?
Solution:
Yes.