Dashes, hyphens and brackets are not commonly used in writing but can be helpful in certain situations. Dashes are used to show a sudden break in thought and set off an appositive phrase that includes commas. Hyphens are used in compound numbers and in multiple-word modifiers while brackets are used to enclose an explanation in quoted material.
Let's talk about dashes, hyphens and brackets. Now these are things that we use sparingly in our writing but they have very very specific purposes, so let's go over why we use them. The first are dashes and that's when you have two dash marks in a row, if you noticed when you're typing it on a computer the computer once you hit space will make it one long dash and that signifies that it's a dash and what we use it for is to show a sudden break in thought or to set off in a positive phrase and that's one of those phrases that renames the subject if we have a positive phrase that uses a lot of commas rather than setting it off with commas we set it off with dashes so Ms. Aquino -- my wonderful, helpful teacher -- otherwise we'd have to many commas here for this to be a clear reference, alright. Hyphens are similar to dashes only it's just one dash mark and what you use those for are kind of some very specific minute details but we want to make sure we get them right. And you use them in a fraction used as a modifier so this is one of those quirks of the English language you're not always going to use them when you write out a fraction like one third but if you say "I ate one third of the pizza" then you're going to want to say one hyphen third. So a fraction uses a modifier, you're also going to use them in compound numbers from the numbers 21 to the number 99, alright. In multiple word modifiers you're going to hyphenate those words and you've got an example right there where we've got two words that are working together to modify this word go ahead and hyphenate them. And then these are just kind of memorization keys you're going to use them with the prefixes ex, self, all and great and you're always going to use a hyphen with the suffix '-elect' or the suffix '-free.' So that's just kind of a memorization thing. The last punctuation mark we're going to deal with are brackets. And brackets are only used to enclose an explanation in quoted materials, so if you're quoting somebody they've said something or made a reference to a person and you need to give more clarification you put that clarification inside of those brackets. So let's take a look at some examples, alright. "The boy claimed that he Mr. Jones wants to be a big star" alright. So if we look here we've got he and we've got Mr. Jones that adds a little bit more clarification, what we can assume is that Mr. Jones is not part of that original quotation but if we leave at he, the audience might not be aware of who he is referring to so as a writer we added Mr. Jones inside of brackets to provide that clarification, alright. In our next example "I have 22 different necklaces," there we've got a number between 21 and 99 so we need to make sure we stick in that hyphen and it's just one small dash there to join twenty-two together. Finally "I love multi word modifiers" so again we've got these two words multi and word working together to modify modifier so we can hyphenate that. And last but not least "she, a hard working diligent young woman put herself through college." So we've got 'she' as our subject and then we've got this phrase that modifies it a hard working diligent young woman. The problem here is that we've got commas in here so that if we set this off with the comma or we put a comma here it gets a little confusing so because we have commas inside this supportive phrase instead of setting it off with commas we're going to set it off with those dashes to kind of really set it apart and clarify what's inside there. So now you've seen the three really specific uses that we have for these punctuation marks and hopefully you can utilize them in your writing.