Carl’s name is Evans. His sister is a Williams. His mum’s name is Mrs Davies.

You certainly need to be on your toes when dealing with this family. Filing correspondence and calling meetings is a nightmare. She did have a relationship once with a Polish gent and we all hoped for a more memorable and consistent surname. It is easy to find a file beginning with Z. Sadly it came to nothing.

We are stuck, waiting for her to meet the love of her life. And when she does you just know that it will be James. We don’t have many surnames up here and she seems keen on trying them all out. It is the sort of thing that happens in Wales.

You have probably come across this yourself. A family with such a confusion of relationships that you wish the kids would just behave themselves in school. It is so much easier if they do. Then you don’t have to write letters home. Because when you do you are bound to get it wrong.

One of the first things you say to students and new teachers is never project your own domestic circumstances upon the families that you teach.

Never assume that the mother or father, or sometimes both, has the same surname as the child.

For lots of our children, what they experience at home bears no relationship to the cosy suburban nuclear family that politicians believe is the bedrock of our society. Look at some classes and stifle a hollow laugh: the children lead emotionally tangled lives, their families awash with shifting dynamics.

I am concerned about attendance, coursework, progress and success. But it is as much as the family can do to remember its own surname. Quite what damage all this does I don’t know. My own family seems boring in comparison. But we all know who we are and how we relate to the other people we see at breakfast.

For many of our children life is not so straightforward. They are all more emotionally tutored than I have ever been but they lack security and certainty. They are aware of dissolving relationships, they are wary of emotion. They are wary of commitment. I am sure that it hardens them.

What is more important? Unhappy parents together? Or happy parents apart? But when things go wrong the consequences are there for all to see in school.

I don’t want to write nonsense about the sanctity of marriage and the importance of family values. All teachers have seen in their classes the consequences of violent and abusive adults who are waiting for children when they get home from school.

All I know is that as we descend through the strata of ability we find more students with disrupted families.

I don’t know what came first, but I know that I can take you to classes in my school where a conventional family is either a rarity or non-existent.

And these are the most difficult classes to manage.

Fancy yourself as a classroom columnist? Email: cymru@tes.co.uk