no saber hacer la o con un canuto
Spanish
Etymology
Literally, “not know how to make an 'O' with a tube”.
Verb
no saber hacer la o con un canuto (first-person singular present no sé hacer la o con un canuto, first-person singular preterite no supe hacer la o con un canuto, past participle no sabido hacer la o con un canuto)
- (idiomatic) to not know one's head from a hole in the ground
- (idiomatic) couldn't organise a piss-up in a brewery