I don’t recall ever being taught this.
i dont what the rules are now, but authors used to use ” ” for dialog, but almost all modern authors use ‘ ‘
then you have fucking cormac mccarthy
The ” is in a way the only right sign in the most of the western world, so always try to use that.
The ‘ is used in rare occasions where you have ” inside “, but in general should you avoid that because it is not correct to use ‘
The apostrophe ( ‘ ) can be used as lesser quotation marks ( ” ) when a difference matters. For instance, sometimes when something is being quoted, the original quote also had a quote inside; you can use the apostrophe to separate the inner quote from the rest of the quote. Other times (such as headlines), there’s a need to separate a title without changing the font the way it normally would (underlining it) but without the emphasis a full quote mark would give it.
As a (popular) example: ” ‘You miss every shot you don’t take.’ -Wayne Gretzky” -Michael Scott. The Wayne Gretzky quote is surrounded by apostrophes, while the Michael Scott quote that was quoting Gretzky is surrounded by the more important quotation marks.
When looking at singular words, they are often used to insert *tone* into a toneless medium, so there are about as many rules as for that as there are accents in a language. Full quotation marks can be used for “sarcasm”, while apostrophes can be used to convey ’emphasis’ or ‘parenthetical thoughts’. As a general rule, quotation marks separate what’s inside from its sentence while apostrophes do the same but with less power.
Edit: This applies to the American English that I’m familiar with. It seems British English might switch the two (apostrophe for quotes and quotation marks for quoted quotes), but my lack of familiarity means I won’t say for sure. I’d suggest further reading if you ever want to write professionally, but the [wiki page](https://en.wikipedia.org/wiki/Quotation_marks_in_English) has some details that might be useful and includes the sarcasm use as well.
Just in case you’re asking about code and not grammar- either can be used to denote a string. They are non interfering so you can typically use either, unless the string contains a single or double quote. Some languages will also allow you to use ` in case the string has both.
On the US, the double quote marks are used to surround a direct quote. Dave said, “man, it’s cold”.
The single quote indicates a quote within a quote. “Dave explained “And then Beth said ‘no, I don’t think it’s cold’. Can you believe that?”
But it’s different in other English speaking places