[clause]のが[X]だ (cleft focus)
syntax3 sentences
The cleft structure [nominalized clause] + のが + [X] + だ focuses on X as the answer to a wh-question implicit in the clause: '[the one who/that did X] is Y.' Compare のは (topical) vs のが (focusing).
3 sentences
The cleft structure [nominalized clause] + のが + [X] + だ focuses on X as the answer to a wh-question implicit in the clause: '[the one who/that did X] is Y.' Compare のは (topical) vs のが (focusing).