Question

somebody cut his finger...........(Question Tag)
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Answer 1

Answer:

somebody cut his finger,didn't it?

Answer 2

Answer:   Didn't they

Explanation: because while we have the same verb in simple past (verb 2) and in past participle (verb 3) then we use did and the sentence is in positive i.e, we have to use the question tag negative and lastly in somebody,anybody,etc   we always use they.