It isn’t easy trying to modify the behaviour of a roomful of naughty monkeys while modifying your own at the same time. “You’ve got to go against the grain,” I’ve been told. To be what I’m not, in other words.

My colleagues tell me I’m far too nice. But isn’t that what you’re supposed to be? I’ve been given sugar lumps for decades for being “nice”, and now I’ve got to be NASTY or I’ll never be taken seriously!

Get tough, get angry. But I don’t feel angry. Pretend then. Oh goodness. I’ve never been to RADA either.

Whichever way you do it, it takes a lot of energy tearing someone off a strip. If you are just pretending - and usually it’s safer than really losing your temper - you also have to contend with the compulsion to laugh.

It has to be deadly serious. You can’t afford to grin when you’re lecturing some miniature unfortunate on the perils of launching paper aeroplanes at your head in lessons. You need to threatening instant annihilation, like one of the ancient prophets.

I have a sudden vision of myself in long white beard and flowing robes, hand raised heavenward like Charlton Heston as the Hollywood Moses. I dismiss the culprit quickly and press my nose to the blackboard before I burst out laughing.

That’s one of the problems - maintaining your composure, the “pretence” of being the Teacher, the Person in Charge. It can come as a shock sometimes that some jolly wheeze in registration - one you would have roared at yourself once upon a time - is now being perpetrated on you!

Take “litter duty”. The class is dispersed to strategic points about the school, armed with wheelie bins. Five minutes later I follow to inspect the troops. I circle the school, refreshed by the peace, the break from bells, noise and stuffy classrooms. Until it dawns on me: I haven’t seen a soul!

No one at the tennis courts, not a single body out by the art block. Where are they all? Simply vanished into thin air. It’s like an Ealing comedy or Jennings and Old Wilkie, and I can feel the eyes watching from the safety of some dark corridor. The trouble is - I think it’s funny too. But since I am the Person In Charge, it means stomping back and getting cross, charging in like a demon and threatening the gallows for neglect of litter duty. Such an effort.

Then there’s Year 9. It’s really hard maintaining my dignity with them. “What’s your name, Miss?” they demand. “Miss,” I reply.

“What do they call you at home, Miss?” “Miss,” I insist.

“We’re going to call you Dave then...”

And because I smile - because I can’t help it - that’s what 1 get called for the rest of the lesson.

Doesn’t look good, does it? The class calling their teacher Dave?

It can be hard being hard. I’m far too soft, I realise that, and I’m working on it - really. But one of the student-teachers told me the other day, as I bemoaned the fact that I was far too patient, “There’s kids out there crying out for patience!” How true, I thought. “Chide them with love,” he said, and I couldn’t help thinking this was probably one of the best pieces of advice I had been given on the course so far.

Chide them with love ...

I still wonder if it’s practical, even possible, but perhaps we should try to keep it in mind as we practise our barks and growls.

Karen McKoy is a PGCE student at the University College of St Martin, Lancaster.