Spelling check on/off when I choose, not automatically

How do I get Word to show red wiggly lines when I tell it "Now check the spelling", and how do I turn them off again when I have checked this?

I do NOT want automatic ANYTHING to occur. Tutorials all seem to be about turning on auto-checking. I am a proof-reader. I am not typing these documents, and moreover I do NOT want the program to change anything. I decide what gets changed. I have turned all the auto-checking off.

The documents are full of unrecognized words, very very few of which are misspellings. I don't want to change them all, or press Return one by one on all of them. I want to see all the red wiggly lines at once, and page through the document ignoring most of them.

At the end I want a clean document, not full of red wiggles, so I want to turn it off.

I'm in an office (so nothing is under my control, I can't download anything for example, or change the registry), where Office 365 has just been installed, replacing OpenOffice or whatever free rip-off we used to have. But in that the spell-check button was a toggle: clicking it turned the red wiggles on, then off, exactly the way I want it.

So how do I see this in Word now, not having to review every single word one by one in a sidebar, but just seeing them all laid out on the page?
Thanks.

Thank you, I've got the auto things turned off. But Review doesn't do what I'm asking. It highlights (in grey) only the first unrecognized word. A sidebar at the left shows the various options to replace it with, ignore it, etc. None of the later words in the document are marked (with either grey highlight or red wiggles).

How do I see all of the unrecognized words at once? I need to just look at the page and see them all marked, the way I used to do, the way I've always done, the way you can in OpenOffice.

(In fact I think even had the words marked in red when it was first installed, but I got too enthusiastic turning options off. Then my main question was how to turn the red wiggles off after I'd reviewed them.)

The IT guy who's going around fixing the disaster that was the upgrade to 365 was very surprised that anyone would ask for LibreOffice to be reinstalled when they had just got the latest Word. I said I never thought I'd say it either. But LibreOffice Writer does it exactly the way I need it as a professional proof-reader, and I've got it back, so that's a fix at least, though not the one I wanted.