Literally, come no (co-mai noh) means nothing. No, seriously: “like no.” That’s the literal meaning of the words.
But in practice, it’s one common locution indeed, and also quite a refined one at that, because it can mean something, or its exact contrary.
And the key to understand the truth lies all in the listener’s ability to detect sarcasm.
In Italy, we use come no to highlight agreement, or that we are able and willing to do something we are asked. Take the little dialogue below, for instance:
Sarebbe bello fare una vacanza. Abbiamo bisogno di riposo. (I’d love to take a vacation. We need some relax).
Come no! Ormai è più di un anno che non prendiamo una pausa. (Oh, that’d be great! It’s been more than a year since we took a break).
Come no shows we are up for the holiday and that we agree with the first statement.
Now, let’s look at this other brief exchange:
Puoi andare tu all’Ufficio Postale? (Can you go to the Post Office instead of me?).
Come no! Ci passo davanti per andare al lavoro. (Of course! It’s on my way to work).
Here, come no stands for the willingness of the listener to do what they are asked.
Insert some good (or not) natured sarcasm and come no turns a sentence into the opposite of what it literally means. It’s all a game of voice intonation, really and, well… reading into someone else’s attitude. If I ask you to clean the entire house because I just don’t feel like to do it myself, you may answer something like come no, in fondo sono la Vostra cameriera, Maestà! (Of course, I am, in the end, your maid, Your Majesty!): it’s pretty evident that house cleaning session is not going to happen…
So, when it comes to come no, make sure you are careful to what people really mean! Or you may not realize the joke is on you!
Tuo fratello? E come no! Lo conosco dai tempi della scuola!
Your brother? Of course, I’ve known him since high school!
Voleva un altro prestito… Come no, sono la sua banca personale, adesso…
He wanted another loan…Yeah, right. I’m his own personal bank now…
Posso aiutarti con la tesi, come no! Sarà un piacere!
Of course I can help you with your thesis, it’ll be a pleasure!