Si conoces a alguien que sea cartero, podemos preguntarle en qué consiste su trabajo.If you know someone who's a mailman or a mailwoman, we can ask them what their work entails.
¿Conoces a alguien que sea cartero, o no? - No lo sé, tengo que pensarlo.Do you know anyone who's a mailman or a mailwoman, or don't you? - I don't know. I have to think about it.