what [someone] did
Tom será castigado por lo que hizo.
Tom will be punished for what he did.
Mary debe haber tenido una buena razón para lo que hizo.
Mary must have had a good reason for what she did.
They must not know what he did.
Deberías haber visto lo que hizo Tom.
You should have seen what Tom did.
Tom ya está arrepentido por lo que hizo.
Tom already regrets what he did.
Tom admitió que lo que hizo estuvo mal.
Tom admitted that what he did was wrong.
Tom no se arrepiente de lo que hizo.
Tom doesn't regret what he did.