To learn the wrong ways of using quotation marks, go to this blog: The “blog” of “unnecessary” quotation marks.
Please note: quotation marks are what you use to indicate dialogue, or actually to quote what someone else said. They can also be used to set apart a word or a phrase, and show that it isn’t part of the sentence structure, but is what the sentence is talking about.
For example, the following sentence:
If you use quotation marks for something that is not recording what someone actually said, or to set apart a phrase whose meaning you’re discussing inside that sentence, then those quotation marks mean, “This is fake.”
When you use quotation marks in any other way than the ways described above, you’re telling your reader that the thing inside the quotes isn’t actually what it says, but is something that is faking it, or hinting at the opposite of what the word itself means.
So if you write something like this —
The office is not for play, but for “work.”
— you’re actually telling the reader that whatever you do in that office, it’s not actual work. You’re doing a winky-winky thing, cluing in the reader that there’s a joke here somewhere. You’re giving the name “work” to what you do there, because it camouflages what you really do.
On the other hand, if you were trying to emphasize that you really do work in that place, and that you’re very serious about it and would never play around, you would write it like this:
The office is not for play, but for work.
That’s how you emphasize a word. You do NOT USE QUOTATION MARKS, because an intelligent reader will recognize that they indicate that the words inside the quotes mean something other than what they say. In fact, the quotation marks usually make the word mean the opposite of what it normally means. Which, of course, is also the exact opposite of what you’re trying to achieve.