Correct me if I'm wrong, but I believe
let ok = NSSpellChecker.shared.checkSpelling(of: text, startingAt: 0).location == NSNotFoundshould reveal if a word is spelled right or not. However, I can find many words that pass this test even though I know they are not words. (Ex: afili, elifile, findethem, findethema.) TextEdit, the source code of which seems to suggest it is also using NSSpellChecker, correctly notes that all these words are misspelled. Am I doing something basic wrong in my use of this API? (I've checked that the language in my case that it's using is "en". Also, none of these words exist in the old-school /usr/share/dict files, which I realize Cocoa doesn't use, but I mention as a sanity check.)
Clues: Some apps catch these spelling mistakes (TextEdit, Mail, Scrivener, BBEdit), while others miss them (Safari, Slack, Twitter for Mac).
Related question: Some words are, as far as I can tell, proper names, which should not included in this test, or at least should be optional. For instance, "askt" comes back as a-ok, but the Look Up service only lists it as the start of a proper name of a journal. Is there a way to disable proper nouns? (One might imagine also using NSLinguisticTagger to help here, but it relies on casing and other clues to know if something is a proper noun and would not help for a lower-cased "askt" string.)
Thanks for any help!