I thought I should write to you about your spawn, X.
Given X's abilities, I doubt whether either of you can read, but I must try. X is by far the most indolent child I have ever been lumbered with. This year he has made no progress at all - zero, zilch. Zippo! If this continues, I fear he will end up as either a circus clown or a politician. I am physically exhausted from trying to beat some sense into him every day. Since this hasn't worked, I'm assuming the fault is on your part. What sort of parents are you anyway?
If you would like to attempt a justification of yourselves and your ghastly child, please ring the school to make an appointment with the principal, who will arrange for the Children's Services Department to make an assessment of your miserable parenting abilities.
Your Sincerely ... etc.
Feel free to change any bits that don't apply.