Spanish for "do you happen to know ... "

Question

If I want to begin a question with something similar to "Do you happen to know [interrogative word] ..." or "Would you happen to know if ... " , then how would you ask it in Spanish?

Sometimes it seems more polite not to assume your interlocutor would have the answer to a particular question. How would you handle asking a question in this manner?

Answer 1

"¿Sabes por casualidad...?

"¿Sabes por un casual..?

En México, hasta donde yo sé, no se utiliza ¿Sabes por un casual? Es más, se enseña a los niños a no confundir casualidad con casual, ni usar esta última palabra para preguntar. - Agora, Jun 8, 2011

Answer 2

En México, hasta donde yo sé, no se utiliza ¿Sabes por un casual? Es más, se enseña a los niños a no confundir casualidad con casual, ni usar esta última palabra para preguntar.

It is a colloquial use, but at least in Spain is common. From the dictionary:

por un casual.

1. loc. adv. coloq. Por casualidad. ¿Has visto mi bolígrafo, por un casual?

That "hasta donde yo sé" sounds to me a bit like a translation from English, by the way. I've always heard things like "que yo sepa".