Today’s commonly confused and misused English words are tough. They’re tough because uninterested and disinterested can be used interchangeably sometimes, but not always.
Both disinterested and uninterested share the following definition: not interested, or not being engaged. However, disinterested has an additional definition: no selfish motive, or unbiased (Merriam-Webster, 2018).
In order to make your writing as clear as possible, disinterested and uninterested shouldn’t be used interchangeably. If you mean something or someone is simply not interested, used uninterested. For example:
Olivia was uninterested in learning English.
The meaning is very clear: Olivia had no interest in learning English. However, let’s switch the adjective around.
Olivia was disinterested in learning English.
Sure, one interpretation is that Olivia simply had no interest in learning English. A second interpretation also exists: Olivia was unbiased when it came to learning English. It may be a bit obvious in this example which meaning was intended, but it may not always be so evident.
As your students’ vocabularies grow, encourage them to frequently consult dictionaries, to ensure their meaning is as clear as possible.