I edit a lot of other people’s work in Scrivener. My previous Scrivener instillation showed open quotes without coinciding close quotes as a red underlined error and as an error during my final grammar/spelling click-through.
I just switched computers, did a fresh install of Scrivener, and can’t find the setting to make that happen again. I’ve googled this question to death and can’t find an answer. Please help–this is driving me nuts.
At most, you may have switched grammar checking on in the past, and it isn’t on by default on a fresh Mac. You can find instructions for spelling and grammar in the user manual PDF, §15.2.5, Spell Checking, and note Figure 15.1, where the grammar check setting is found.
If that doesn’t do it, perhaps you had something else installed, like Grammarly or ProWritingAid, which can augment other software like Scrivener with more sophisticated grammar checking than what macOS itself provides.