on the subject
Depois, ela tocou no assunto, e eu tive que confessar de onde tirei.
Then she brought up the subject, and I had to confess where I got it from.
— Os Incompreendidos (1959)
Nem sequer se pensava no assunto.
It wasn't even something anyone thought about.
— Os Bons Companheiros (1990)
Ele pensou no assunto durante três dias.
He thought about it for three days.
Pediu que eu não tocasse no assunto.
He asked me not to bring up the subject.
Ele falou como se fosse especialista no assunto.
He spoke as if he were an expert on the subject.
Aproveite estes dias para pensar no assunto.
Use these days to think about it.
Certo, mas continuarei pensando no assunto.
Right, but I'll keep thinking about the matter.
— As Diabólicas (1955)
Vou pensar no assunto e te respondo depois.
I'll think about it and get back to you later.