Same here in Portugal, and as caseydog said we use the knife to push food into the fork. Some of my American colleagues cut their meat before they started to eat so they never had to switch between fork and fork + knife. Here in Portugal it's considered rude to eat using only the knife although only the elders care about that, most people don't mind.Yep - this came up before. I find it very odd as it means that to cut anything up I assume you have to change the fork to the other hand and then put the used knife back on the table (ugh). Most Brits tend to eat with a knife and fork unless its casual eating on the sofa (which I personally hate).
I have a portuguese friend who eats only with the fork when she's very tired or feeling down!