Some of the spelling words taught in elementary schools for the first 150 years American was a nation included words like:

contumelious
ichthyology
bronchotomy
loquacious
mendacity
armigerous
vertiginous
oleaginous
acanthus,

and many other such words. On my own sixth grade spelling test was the word antidisestablishmentarianism.

Today, even those who write professionally may use "reign" when they should have used "rein" and "breaks" when they should have used "brakes," simply because they depend too heavily on spell check, which won't catch errors like that.

One fellow I know who has a PhD spun out a memo telling others to be "discrete" when he obviously meant "discreet."

We depend on spell check far too much and most who struggle with spelling are quick to say they can't spell words right. Everybody makes spelling/typing errors, but we should learn not to be "dumbed down" by spell-check on our phones and computers. - Richard McCuistian