John-wa [dono gakusei-ga Smith sensei-ni at-ta ka] sitteiru-ga [Brown sensei-ni-wa (*sore-ga) dono gakusei-ga ka] sira-nai.
John-Top which student-Nom Smith prof.-Dat meet-past Q know-but Brown prof.-Dat-Top (it-Nom) which student-Nom Q know-not
John knows which student met Prof. Smith, but (he) doesn't know Prof. Brown, which student (it is).