You might've heard about Will Ferrell's new comedy, 'Casa de mi Padre'. He plays the son of a Mexican rancher who ends up battling a drug lord and almost the entire movie is in Spanish with English subtitles.

It comes out next Friday, and the trailers have been out for a while. But has a new clip where Ferrell and Efren Ramirez (a.k.a., Pedro from 'Napoleon Dynamite') sing a song called 'Yo No Se', which means 'I Don't Know.'

In case you're wondering, Will took three years of Spanish in high school, and two semesters in college.