Place all quotes that are less than two sentences long inside "double quote marks".
"Depending on the referencing style you are using, you need to add either an in-text citation directly after your quote" (often the authors surname, the year of publication, and the page number) or sometimes you need to add a superscript number and then a footnote instead.
If you use any bibliographic details in the sentence or paragraph that introduces your quote, then you can leave those details out of the in-text citation. For instance, if I said that on page 25 of his play, The Tempest, Shakespeare described a poor man's library as a "dukedom, large enough" (2015) then I would only have to put the year of publication in my in-text citation, as I have already given the author and page number.
Full stops go "after the closing quote marks".
"You should avoid having quotes as whole sentences".
You can "take small bits out of a quote by inserting three dots... in place of the missing text", provided it doesn't misrepresent what the author was trying to say.
You can "add small bits in by putting the [new text] inside square brackets", provided it doesn't misrepresent what the author was trying to say.
Do not place quotes that are longer than 30 words in quote marks.
Instead, you should make the quote an indented paragraph (me, now, p. 1).
There is no need to put long quotes in italics, plain text is fine.
The full stop of the last sentence goes outside the closing bracket for the (in-text citation).
You can take small bits out... and [add bits in] to long quotes in the same way as you do for short quotes.
Sometimes you want to quote an author who is quoting somebody else. For instance:
It is always better to quote the original or 'primary source' than use a quote within a quote (because it is more authoritative).
But if you can't find or get access to the original you should reference BOTH texts in your in-text citation and ONLY the text you actually used in your reference list. For example:
"Elves are green" (Grinch 2007 cited in Santa 2013, p.99)
https://owl.english.purdue.edu/owl/resource/619/1/