Happy St. Patrick's Day! Make sure you are celebrating it the right way. That means, when you shorten the word, you make it 'Paddy' not 'Patty.' Really, this is what's right. Stop making this mistake.

The reason it's D and not T is quite simple. The website PaddyNotPatty.com explains it really well:

Paddy is derived from the Irish, Pádraig: the source of those mysterious, emerald double-Ds.

Patty is the diminutive of Patricia, or a burger, and just not something you call a fella.

There isn’t a sinner in Ireland that would refer to a Patrick as “Patty”. It’s as simple as that.

For more reference check out the video below (which features some NSFW language) and make sure you are celebrating right today.