Pronoun Agreement
Pronoun agreement can be trickier than it might seem on the surface. The rule is that we must make sure our pronouns agree in number and gender with the nouns they are replacing. For example, when we write a sentence about a girl named Sophia, we would use she as the pronoun to refer to her.
But things get a little more confusing when we are talking about a kind of abstract person, and to avoid sexist language, we cannot say he or she. Instead, we should say he or she, but people sometimes just say they, which does not agree in number. Here is an example:
If you want a child to learn, it is helpful if you make learning fun for them.
Although you'll often hear people use this plural pronoun to refer to a singular noun in speech, it's technically incorrect to do so. This is something you'll want to be aware of in your writing.
Here is one way to correct the error:
If you want a child to learn, it is helpful if you make learning fun for him or her.
Here is another way to correct the error:
If you want children to learn, it is helpful if you make learning fun for them.