Ask questions or just talk about different languages. Since BrainKing is an international game site supporting many languages, this board can be kind of useful.
This isn't my bill. There must be an error. I made an error about Julie. She's nice, really. It was a huge error to send her to boarding school. A week after the wedding she realized she had made a terrible error.
>Make no mistakes, we're facing a major financial crisis.<this is a different use of mistake. Kind of idiomatic and it won't look or sound right putting error in its place.>The accident was the result of pilot mistake.< This might be a legitimate sentence, but as you have it is the way I always heard it.
Rising costs have left us very little margin for mistakes.