I stumbled across a nice feature on the Instituto Cervantes site the other day: The Museo de Horrores, a collection of errors commonly made by native speakers and students of Spanish. It's worth checking out, even if just to pat yourself on the back for all the mistakes you DON'T often make!

Here's the Museum of Spanish Horrors. And here's hoping you don't recognize yourself there.

A few of the common errors covered:

A nivel de

Deber/deber de

Porque (el porque, por qué, porque, por que etc...)

Mayúsculas - rules for when to capitalize in Spanish

Aun, aún

Leísmo, laísmo, loísmo

oír o escuchar?

We've got a list of common errors on the don Quijote site as well, while you're at it. I'm hoping to kill a few of my own bad Spanish habits in the new year. (Here's the don Quijote common errors page in Spanish.)