Fourty-For

I was simply writing a cheque, but after I'd written it, I sat there staring at it for a moment.

Forty pounds only.

I then had one of those bizarre moments where you're sure something is right, but it looks wrong. "Forty.  Forty.  Doesn't 'four' have a 'u' in it? But that is how you spell 'forty', isn't it."

I had to write them both down to check ;)