Pronoun-antecedent agreement refers to the correspondence between a singular noun (or antecedent) and a singular pronoun, or a plural noun and a plural pronoun. Therein, in the sentence, the singular noun phrase<em> an enslaved person</em> does not match with the plural pronoun <em>their</em>. As a result, the revised version of the sentence would be:
<em>It was common for </em><em>an enslaved person</em><em> to stop there on </em><em>his or her</em><em> way to the North.</em>
He is right because human intelligence may not be completely dependent on the grades and tests done at younger ages. Intelligence could come in many forms and in many different subjects. Not everything taught at school could be part of someone's intelligence, and that person could have strengths in other topics outside of the grades and tests done.
