Win 10 Spell Check - How does it work?

07/03/18 I'm using:
Win 10 Pro, Version 1803 (OS Build 17134.112)

If you go to (please see screen shot): Settings / Devices / Typing

I put the slider to "on" here for everything, except:
1.) Add a space after I choose a text suggestion
2.) Add a period after I double-tap the Space bar
3.) Show text predictions based on the recognized languages you're typing in

Question #1
Shouldn't "Highlight misspelled words" be
"Put a red squiggly line under misspelled words"
. . . right-click on the body of text in an e-mail / Check Spelling
because that is apparently how it's "highlighting,"
it's not like it's using a "yellow highlighter" on your misspelled words,
I think the description here is bad

Question #2
Is Win 10 Spell Check like the "Grammarly" Firefox Add-on?
https://addons.mozilla.org/en-US/fir...n/grammarly-1/
. . . where all the text you type goes to a server somewhere to determine the spelling errors?
. . . or does it use a dictionary and thesaurus on your computer? I would hope.

It says "Highlight misspelled words," and to me, "highlight" means a "yellow highlighter" . . . It took me a couple of months to realize that it's not that the Win 10 "highlighting" feature isn't working - No, that red squiggly line is what it means by "highlight" . . . Also, look around on the web, many people think that Win 10 Spell Check doesn't work, probably for a reason like this.

It would be better to say "Indicate misspelled words" . . . and then give you choices - examples of what you'll see - like a red squiggly line, or maybe various highlighter colors, like you see in Word

. . . Much more importantly, the Settings text on this sets the wrong expectation- that the spell check is universal. It's not

Yes. It would be nice if you could have an indicator that Spell Check works on some program, or, be able to use it anywhere somehow.

. . . try disconnecting your internet connection and see if spell check still works then

I mostly only notice Spell Check when writing a Yahoo e-mail.

If I disconnect from the internet, maybe it goes to a dictionary on your PC, who knows, I don't.

Where does it say how Spell Check actually works? . . . Maybe this is the reason why I heard it said that Win 10 itself is malware (but it works so great!).

Maybe Win 10 Spell Check sends everything you type to a dictionary and thesaurus on a Microsoft Server somewhere, and your Custom Dictionary is just words that you added.

Any idea who knows how it actually works?

There's no way for "Joe User" here to know, otherwise.