Here are some key points:
* It's the opposite of bilingualism or multilingualism: Bilingual people speak two languages fluently, while multilingual people speak more than two.
* It can be a result of different factors: These can include location, upbringing, education, and personal preference.
* It doesn't mean someone can't learn other languages: Monolingual people can still learn new languages if they choose to.
It's important to note that the term "monolingual" is often used in a relative sense. For example, someone who only speaks English might be considered monolingual in a country where other languages are spoken. However, they might still have a good understanding of other languages through exposure or education.