I'm writing a story involving two characters, both of whom speak English as a second language - the first character is Spanish, the second is Russian. I would like to know what are some common mistakes native Spanish/Russian speakers make when speaking English as a second/third language? Of course, the mistakes I make in Spanish/Russian are not the same as others would make, so a better question might be: if you are a native Spanish/Russian speaker, what are some mistakes you make in (American) English?