So here are a couple of videos from the same guy. They are quite sweary so if you have a portuguese relative within earshot, you might want to use headphones. I was interested in the prepositions more than the swearing and I’ll tell you why when you’ve watched them. In fact, the whole post is quite sweary, even the English bits. If you are a child, reading this, please ask your parents to hide your device until your eighteenth birthday and then carry on reading.
OK, ready? Good. Happy birthday, by the way.
As you can see, he’s pretty funny. In each case he’s giving versions of the same expression:
Não faz frio nem orvalho mas está a chover para caralho.
Não faz chuva nem orvalho mas está um frio do caralho
If you don’t already know, caralho is one of the rudest words in the language. But what’s going on with those prepositions just in front of each? Why is it para in the first instance and do in the second? I threw the question open to the floor.
In both cases we’re using the bad word to emphasise how strongly we feel about the situation, but you lead into it with para when what you are emphasising is a verb. “Esta a chover para caralho”, “Os ovos andam caros para caralho”, for example.
On the other hand, if its a noun you’re emphasising, you lead in with do: “Está um frio do caralho”, “Cão do caralho passa toda a noite a ladrar”
It’s hard to draw a direct analogy to English swearing, not least because we wouldn’t even say “está um frio…” (“it’s a cold”). We’d treat frio as an adjective, not as a noun. But I’m sure you’ll be familiar with the fact that swear words are pretty flexible in how they’re used. So you could have ‘It’s cold as fuck” or “It’s raining like fuck” or “It’s a huge fucking storm”. Portuguese seems to have a rule about how the caralho is linked to the thing it’s referring to though so it seems to be one of those rare cases where portuguese is less complicated than English.
Taking a break from the lizards today to compile Instagram posts I made as part of 
Luso 