Most of us have been typing on keyboard without knowing this hideous trick. Can’t be blamed for how keyboard is designed.
"The straight quotes we know" “The curly quotes”
The straight quotes is exactly the same for the left and right, while the curly quotes are not. The curly quotes looks like 66 and 99.
How to Type Curly Quotation Marks
To type curly quotes on a Mac, you have to type
Option+[ for opening, and
Option+Shift+[ for closing.
If you want single and not double quotes, type
A keyboard trick worth knowing!