I was having an interesting conversation with a couple of my coworkers the other day about how the teachers at our uni think about the students. Obviously some of them (I hope me!) treat them with kindness, and respect. Others think that the students are total idiots because their English ability is so low. The thing is, we work at a science and engineering school so most of our students are in these fields and obviously languages are not their strong suit, science and math is. Just because someone is bad at English doesn't mean that they're a moron. My coworker mentioned that if people judged his intelligence based on his Korean ability he'd rank somewhere in the 3-year old toddler range.
So what I'm saying is this: treat your students with respect, even if they don't know a word of English. They are probably very good at something else. Or, have just had a hard few years but life will get better for them later. Or, they just want to be a taxi driver, so who really cares if they speak English or not. As a teacher, you have a chance to show kindness and love, and have a positive influence in people's lives. Starting with the basic premise that your students are stupid idiots is not a good way to do this.