Business (now that's a good one, English is my third language and this one took me about 10 years to remember. Obviously I don't work in business.)
busy + ness - the two morphemes in the word
Apply spelling rule/ usual pattern (though don't doubt there are exceptions) - of When a word ends with a consonant plus y, you must change the y to an i^ when you add another morpheme.
so:
happy + ness = happiness
worry + ed = worried
heavy + est = heaviest
early + er = earlier
I seem to remember that was how it was dealt with in the spelling program my DC are doing. Though I then have to sort of say to them in business you are busy to ensure they remember how to break that up into morpheme correctly as it's not as obvious as the others I listed.
I find we are tending to do that anyway - Ghosts have hosts for example, where has here in it as does the place there - so cover first letter you are here - wrist, watch are all hand related so five letters long same as five fingers so if they end up with more than that because they've added h after w they know to look again.
Hopefully as the spelling become more embedded they won't need these things it will be automatic. On plus side eldest DC is now when given a list of spelling is looking at pre/suffixes and then breaking root words into the phonics sounds and just focusing on any non standard tricky bits. It does mean it taking her less time - though it's a massive help the lists currently have a point/pattern involved and aren't random or ones almost designed to cause confusion that we've had in the past.