Many of us enter teaching determined to avoid the dark sarcasm of the classroom. But it isn’t that simple. Teacher-talk is something deep-rooted and difficult to avoid. For example, it is heavily repetitive. Probably more than any other professional body, teachers spell things out: “Today we’ll be studying proteins. We’ll start by looking at what proteins are. Then we’ll look at what they do. Then we’ll do an experiment to test some proteins ourselves. Let’s start by seeing who can tell me anything about proteins. Shelley, what do you know about proteins?” This is classic teacher talk - clear, repetitive, highly explicit and reassuring to most listeners. It is also, like most teacher-talk, full of questions. Teachers use questions like chefs use olive oil. They are a core ingredient of our language. Sometimes questions are genuinely exploratory - “which other capital city has subway systems like this?” Occasionally they are open-ended (“what do you think?”), and - most controversially - a form of social control: “Peter, why aren’t you listening?” Teacher-talk is also full of imperative verb forms - commands and orders that we’d rarely think to use in everyday life. “Right, sit down. Get your books out. Leanne, pay attention.”

So these are some of the traits of teacher-talk that we might be aiming to avoid. That can, however, lead you to a different dark side - the risky territory of seeming to aspire to trendiness. This is the hazad of changing the way you talk in order to show that you’re on the kids’ wavelength.

It is disarmingly easy to slip into language patterns that students regard as their own. This is the old Grange Hill cliche of the hesitant new teacher who perches on the edge of the desk for his first lesson and says:

“Hi, call me Dave.” Most students loathe this. They become embarrassed when a teacher tries to be trendy. Teachers can’t be trendy. It’s not a trendy profession.

One pupil told me that he finds it “brain-numbingly naff when teachers go into their sports casual, laid back mood”. Another put it more bluntly. She says that any teacher who says “cool”, “chill” or - worst of all - “wicked” is asking to be laughed at. He or she might as well just wear a badge that says: “I am trendy, dammit.”

Linguists describe this as code-switching, the process by which we adjust our language according to the situation. We all do this, and it’s worth bearing in mind that our students do too. One sixth-former recently told his tutor that he had sold his DJing equipment. This trendiest of students was heard to say: “I’ve managed to trade it all in and buy a rather splendid collection of sociology textbooks.” He was adjusting his language to speak to a teacher.

When teachers do the same thing in reverse, it can backfire badly. We may wish to show empathy with our students. In reality, we can end up reinforcing some of the old stereotypes about teachers who try too hard to be popular or fashionable.

Geoff Barton is deputy head at Thurston Community College, Suffolk