If you park by the fire hydrant, they will give you a ticket. The pronoun "they" looks like it refer to "the fire hydrant". This is incorrect. A fire hydrant is a singular thing; therefore, it cannot be replaced if the pronoun they. "If you park by the fire hydrant" becomes a dangling modifier that needs a correct noun to modify. Hence, "they" is an (1) indefinite pronoun that needs to be replaced with a specific noun. We can then say instead: If you park by the fire hydrant, the officer will give you a ticket.