Answer:
It's a prediction in the plot of the story. Example: "He knew that bad things were to come." This shows that there was a prediction of things to happen.
In the sentence "They say we will not be able to afford to own houses in a few years." there's a <u>pronoun reference</u> error. It is unclear who the pronouns<em> they </em>or <em>we </em>are referring to.
Pronouns are used to replace nouns, and it is considered to be a pronoun reference error when the reader is unable to deduce from the text the noun being replaced by the pronoun.