Apostrophes are used in three different scenarios. In writing, apostrophes are used to (1) form possessive nouns, (2) show omission of letters or (3) to form a plural of lowercase letters. When forming possessive nouns, we add "'s" to singular words that don't end in 's' and plural words that don't end in 's' and compounds words.
So let's talk about apostrophes, now apostrophes are one of the simplest punctuation marks but I think one of the trickiest to use. So let's talk about the three basic rules here, you use apostrophes first and probably most often to form possessive noun, so if I've got the noun 'Sarah' I'm going to add an 's to make that possessive. We also use apostrophes a lot to show the omission of letters and that's kind of a fancy way of saying make a contraction. So when we've got 'could've' we have that apostrophe in place of letters 'ha', so instead of 'could have' and then this one isn't used very often but you never know, you use apostrophes to form the plural of lower-case letters, so somebody is telling you to mind your p's and q's it's 'p' apostrophe's, 'q' apostrophe 's'. Alright, now here's where we get kind of a little mudded up and this is kind of an easy way to remember it, there's two basic rules for how to make things plural and how to deal with your apostrophes. The first is to add an 's and you do that when the following is true, so you add an 's to a singular word that doesn't end in 's' like student, you add 's to make it possessive or when you have a plural word that doesn't end in 's' like the word 'geese' that describes a flock of geese, if we are saying 'the geese's flight path' we just add that 's there. Now the last two are kind of sticky ones but these are good ones to remember, when you have a compound word one of those hyphenated ones like 'brother-in-law' you are going to add the 's to the end, so it's 'brother-in-law's' and then when you have joined possessions so 'Susan and Bruce's dog' you are going to add the 's just to the last noun of that joined possession, so that's another thing to remember. The other option that you have is adding just an apostrophe and you're only going to do that when the singular or plural nouns end in 's' so something like the Joneses' which is a plural noun that describes all the members of the Jones family, if we are talking about the house that they own, we are going to say the 'Joneses' house or for talking about a lot of lasses maybe we are talking about Scotland or something, instead of adding s's so we've got three s's in a row, we just need to throw this apostrophe here on the end to show that they posses something, so those are the two basic rules. Alright, let's take a look at some tricks that will help you remember them, the first one I have is don't get apostrophe crazy, so we use them mostly to show possession and we use them in contractions. These I think are the three times and it's most often easy to get these mixed up, so things to remember is it's, they're and you're, those contractions when you have an apostrophe in them are always contractions, they never show possession, I know that's kind of counterintuitive because we think apostrophe equals possession, in these cases it doesn't it's only a contraction. So it's means it is, they're with an apostrophe, they are, you're with an apostrophe, you are. If you want to show possession you just leave out that apostrophe, so its or in the case of they're you change the form to t.h.e.i.r or your y.o.u.r. So that's just something to kind of keep in mind. And then also don't use apostrophes to make things plural, so we never use an apostrophe if it's not possessing something or omitting something. Let's take a look at some example. Alright 'I think you can find that in the childrens section', so we've got 'a section' and it's the last thing and the section is belonging to the children, so when we've got this apostrophe here we've got a plural word but children doesn't end in 's', so we are going to throw the apostrophe between so it will be essentially like adding the apostrophe in the 's' alright. 'We want to honor both of our families traditions' and I think this is kind of a difficult one, so obviously the traditions are the things being possessed alright, they belong to our families since families is a plural and it ends in an 's' all we have to do to show that possession is add that apostrophe to the end, alright.
And finally 'mind your ps and qs when your in the house built in the 1880s' we've got to fix a couple of things here, so we've got p's and q's because we said that one not often used rule is that you separate the lower-case letter from the 's' to make it a plural when it's having apostrophes, alright and then we've got 'your' and there is something wrong with this 'your' here alright; this 'your' shows possession but we are trying to say 'you are', so we've got to throw an apostrophe in here and change the form, alright. And then finally some of you may be wanting to throw an apostrophe here after 1880's but remember the rule was only with lower-case letters, so this is something I see a lot, you never want to throw an apostrophe in when you are making a time period plural, you just add that 's' there. So there's a couple of different things that you can look out with how to use an apostrophe and hopefully I made it a little bit more simple.