The Mistral is a strong wind that you will experience mainly in winter and early spring in Southern France and Sardinia! And boy, that Mistral sure can blow!!! When we decided to go to the beach it was an especially windy day, so the fine sand was blown in our faces and walking was a little strenuous!
Back in Cagliari I was even hit by some sort of plaster being ripped off a wall of one of the old houses in the Castello district! So watch out!
If you decide to come to Cagliari by car you will find that parking your car is a real problem - especially in the old part of town! Okay, there are parking lots, but even those are full most of the time. What are the options? Public transportation is one or taking chances and renting a tiny car - like my all time favourite Fiat 500!
In the Marina and Castello districts of Cagliari the streets are so narrow that it is difficult both for car drivers and pedestrians to pass by eachother! I found walking there a little annoying at times, but on the other hand I would not have wanted to be a driver either.....
Although many millions of Brits go to Italy every year, the Italians aren't so hot on English. In particular, I found very few Sards that could speak English. They have their own language as well, but if you have some knowledge of Italian you will get by in Cagliari fine. In Alghero they speak Catalan so knowledge of Spanish will come in useful. However, most of Sardinia speaks Sard or heavily accented Italian.
'Si' is expressed as 'ayyar' (yes)
There are many gypsy women begging with their children in Cagliari. They have been known to steal bag contents whilst another is keeping the victim's attention. You can't help feel sorry for them but be wary.
When I was there( a few years ago) Cagliari was absolutely beset by degenerate teenagers . They're mostly quite beautiful, but they're also hustlers and there are quite a lot a lot of them. Chat with them at your own risk. Also, compared with most of the rest of Italy, Sardinians seem reserved to the point of veiled hostility. This is a huge generalisation of course.