In linguistics and grammar, a pronoun (Lat: pronomen) is a pro-form that substitutes for a noun (or noun phrase), such as, in English, the words it (substituting for the name of a certain object) and he (substituting for the name of a person). The replaced noun is called the antecedent of the pronoun. For example, consider the sentence "Lisa gave the coat to Phil." All three nouns in the sentence can be replaced by pronouns: "She gave it to him." If the coat, Lisa, and Phil have been previously mentioned, the listener can deduce what the pronouns she, it and him refer to and therefore understand the meaning of the sentence; however, if the sentence "She gave it to him." is the first presentation of the idea, none of the pronouns have antecedents, and each pronoun is therefore ambiguous. Pronouns without antecedents are also called unprecursed pronouns. English grammar allows pronouns to potentially have multiple candidate antecedents.
Some topics can be challenging to create lesson material for so there are sections for a wide array of ESL topics on the site. This section is dedicated to pronouns; take a look at some of the 347 pronoun worksheets to find something that your students will enjoy. Many teachers have used this worksheet to give their students more practice using demonstrative pronouns. It is very straightforward with a brief review of the uses of this, that, these, and those followed by some fill in the blank sentences for practice. Be sure to create an answer key for yourself to make answering questions and giving corrections in class easier. There are other great worksheets here too so make sure you look at a few other them before deciding what you would like to use in class. If you want to you can even combine the exercises from several worksheets to make your own customized handout.
Pronouns are words that take the place of nouns which sounds simple enough except that there are lots of different kinds of pronouns. In order to help students understand this material clearly, subjective pronouns are usually covered first with other types of pronouns coming later in the course. Make sure students understand one set of pronouns before moving on to new material. Here is a link to a fun YouTube video about pronouns that your students might like. It clearly demonstrates the important function of pronouns.