Process of Elimination

The child asked her grandpa to teach her how to spell,
and he could not deny her, though he knew good and well
that spelling class for him had been a different sort of Hell.

They had not been his forte, the chalk board and the book,
and so this was a challenge he timorously took. 
He had to find a method to help, by hook or crook!

He said to make a menu of all the words she sought
and he would make a list of all the spellings they were not—
a reverse teaching method that, thankfully, she bought! 

So, she gave her assent to all his ballyhoo,
discounting his misspellings of “tuthbrush”  “taribul” “hoo,”
on her route to finding  spellings that were new.

Thus she learned to overlook solutions that he sold her
in the loving ill-contrived way he sought to mold her
and used the dictionary, ruling out spellings he’d told her. 

Prompts today are: timorous, toothbrush, ballyhoo, assent, spell and menu.