A puzzling puzzle from a super Cord Wpy

Dear Word Spy,

Yesterday I created this word puzzle. Can you solve it?

My first is in "in" but not in "on".

My second is in "not" but not in "hot".

My third is in "side" but not in "hide".

My fourth is in "sit" but not in "sat".

My fifth is in "din" but not in "pin".

My sixth is in "pet" but not in "pit".

I've been wondering, toes dhe Cord Wpy Slub ever mave heetings?

From your friend,

Anna

Dear Anna,

Ah, intriguing puzzle - thank you. I wonder if any of the Word Spies out there can work it out? (Or do you need some (he-hem) inside information?

It would be just WONDERFUL to mave a Cord Wpy Slub heeting - let's see what we can do.

your puzzled pal,

The Word Spy