Terribly sorry to interrupt but you may or may not be aware that some on here think I can be a bit of a spelling/grammar nazi so I felt it only proper that I step in here and stop you because you're completely wrong in what you're teaching here.
Quotation marks should only be used for
direct quotes which are by definition
verbatim so really you should never put a made-up quote in quotation marks of any kind. You also
never use quotation marks when paraphrasing as paraphrasing is the very opposite of quoting. Quotation marks may also be used for emphasising a word or idea although some prefer that you use italics or underlining in such cases. Whether you should use a single or double quotation mark is a matter of style because as I'm sure you're aware English doesn't have any sort of governing body so it's left to the individual/organisation to decide. The only real rule is that you be consistent.
It used to be that in British/Australian English the single quotation mark was preferred and that the use of a double quotation mark was only acceptable when quoting inside a quote. For example:
Trala said, 'Witty Banter told me, "You're not using the correct quotation mark!" '.
The reverse is so in American English.
Trala said, "Witty Banter told me, 'You're not using the correct quotation mark!' "
Due to the difficulty in conveying sarcasm and/or hyperbole in text it's become acceptable, albeit still wrong, to use quotation marks for made-up quotes in informal writing. And for those places that follow British usage the double quotation mark is usually favoured because it would not be used for a real quote (thereby distinguishing it from such) and also because it resembles air quotes. It is however just as acceptable to use single quotation marks because neither is technically correct.
Anyway, that's all I wanted to clear up so we can now return to our regular programming.