My older son Kit, who’s nine, bears the brunt of my obsession with the English language.

“It’s brought, not brung”, I correct him (several times a week). “We say written, not writ.”

Most of the time, he puts up with this with good grace. (“Do you tell your grown-ups that?” he asks).

A couple of weeks ago we were out shopping for presents for my other son and my husband, who have birthdays in the same week.

I was just buying a jumper for my husband when I couldn’t find my credit card and realised I had left it in the self-service till at WH Smith half an hour earlier.

“I hope no one has tooken it,” gasped Kit as we sprinted back at 100mph.

“Taken!” I said. “You hope no-one has taken it! And so do I.”

Kit started laughing. “Mummy, even when we are in the biggest rush ever you still correct what I say.”

It made me laugh too. I’m afraid I just can’t help it.

There’s a happy ending to the story –  my credit card was safely behind the counter at the shop. Many thanks to the person who found it and brung it back.