An apostrophe is a punctuation mark used in the English language in a variety of ways, based on some simple rules of grammar. In spite the simplicity of using this punctuation mark, it is often the one mark which is most incorrectly used by most people. To learn how to use apostrophes in the correct way, read through the few rules of grammar listed below.
Using apostrophes to contract words. This is the most common use of apostrophes; when certain words are contracted, one or more of the alphabets in that word are replaced by an apostrophe instead. For example, "she is" or "he is" can be contracted to "she's" or "he's". The exception to this general rule is the difference between a contraction of "it is" and the possessive pronoun "its". No apostrophe is used when the word ‘it' is used as a pronoun, but when used as a contraction of ‘it is', the word is depicted as "it's", the apostrophe taking the place of the letter ‘i'. Similarly, no apostrophes should be used for other possessive pronouns such as ‘yours', ‘his', ‘hers', etc.
Apostrophes are not used for plural words. A common mistake made by most people, is to tag an apostrophe before the letter ‘s' when using the plural form of words. Common words where this mistake is made are ‘apples', ‘markets', ‘mangos', etc. The apostrophe is mistakenly added instead, to form these words - apple's, market's and mango's - adding the apostrophe actually turns the word into its singular form.
Signifying possessiveness for singular nouns. Use apostrophes to denote the possessiveness aspect for singular nouns. For example, "the flower's smell", or "Dorian's portrait', etc. If there are two singular nouns and both share equal possession of an object, then an apostrophe is added only at the end of the second noun. Example - "Jack and Jill's child"; for separate possessions, the apostrophe will be used at the end of each noun. Using the same example as above, if Jack and Jill each have their own child, then the correct usage will be "Jack's child and Jill's child".
Denoting possessiveness for plural nouns. In contrast to singular nouns as in the previous step, the usage of apostrophes for denoting possessiveness for plural pronouns, depends on whether the noun ends with the alphabet ‘s' or not. For example, if the word used in plural form is ‘girls' in the phrase ‘girls hair', then the apostrophe is added after the last letter and not before it - girls' hair and not girl's hair. For plural nouns which do not end with ‘s', like the word ‘children', then, an apostrophe should be added before the ‘s' to denote possessiveness - "children's toys".
Keeping these simple rules in your mind while using apostrophes will make sure that you use them correctly. Correct usage comes with practice, hence, next time you write, put down the words on paper and then practice adding apostrophes as discussed above.