Expletive pronouns are words that function as pronouns but refer to no specific antecedent. They are important to the flow and meaning of a sentence, but they are not actually replacing any person or thing like a normal pronoun would. You may also see these words referred to as “dummy pronouns” or simply as expletives. There are only two expletive pronouns to remember: it and there.
It is most commonly used as an expletive pronoun in discussions related to weather, time, and distance.
It is rainy today. It is 2:25. It is a short drive to the store from here.
Although we instinctively know what is being said in each of the examples above, there is technically no antecedent for it to refer to in any of the sentences. We could reword the examples to get a more specific idea of what it might refer to:
The weather is rainy today. The time is 2:25. The drive to the store from here is short.
It can also be used as a dummy pronoun to introduce a concept or idea to follow in a sentence. This type of it is sometimes called anticipatory it.
It was nice of Ron to lend us his books. It's so good to see you! It looks like you need a vacation.
There is commonly used as an expletive pronoun to indicate existence. When there is used to state existence, it is aptly named existential there. Take note that when there is used to indicate existence, it is not the subject of the sentence and has no antecedent. The subjects below are written in bold. If you struggle to find the subject in sentences like these, try asking who or what is existing.
There was a stray dog outside earlier. There are really good cookies at the fundraiser. Once there was a bear in our backyard.
Be careful not to assume that there is always an expletive pronoun. Remember that there can also function as an adverb to indicate where an action takes place.
The cat was sleeping there. The rest of the group is already waiting over there. We already ate there last week.