Try teaching it German compounds. I’m a big fan of artisanal compounds, but getting spell check or the swipe-o-matic to accept them is an unwinnable battle.

I have a spelling checker,
It came with my PC.
It plane lee marks four my revue
Miss steaks aye can knot sea.
Eye ran this poem threw it,
Your sure reel glad two no.
Its vary polished in it’s weigh.
My checker tolled me sew.
A checker is a bless sing,
It freeze yew lodes of thyme.
It helps me right awl stiles two reed,
And aides me when eye rime.
Each frays come posed up on my screen
Eye trussed too bee a joule.
The checker pours o’er every word
To cheque sum spelling rule.
Bee fore a veiling checker’s
Hour spelling mite decline,
And if we’re lacks oar have a laps,
We wood bee maid too wine.
Butt now bee cause my spelling
Is checked with such grate flare,
Their are know fault’s with in my cite,
Of nun eye am a wear.
Now spelling does knot phase me,
It does knot bring a tier.
My pay purrs awl due glad den
With wrapped word’s fare as hear.
To rite with care is quite a feet
Of witch won should bee proud,
And wee mussed dew the best wee can,
Sew flaw’s are knot aloud.
Sow ewe can sea why aye dew prays
Such soft wear four pea seas,
And why eye brake in two averse
Buy righting want too pleas.

Jerrold H. Zar.