macOS automatically check and correct spelling mistakes while you're typing. This is a handy feature but for someone like me who don't always type in perfect English on purpose, it's more of a nuisance. Even more so is for those who communicate via other English or Roman alphabet-based languages.
macOS can be disabled from
Finder's configuration menu.
Spelling and Grammaroption.
Correct Spelling Automaticallyto remove the tick mark.
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