* Data collection is inconsistent: Different countries and organizations use different methods for collecting language data, making it difficult to compare statistics.
* Defining "language" is complex: What counts as a language vs. a dialect is often debated. Some people consider different dialects of the same language as separate languages, while others don't.
* Language skills vary: Someone might be considered bilingual if they can hold a basic conversation in another language, but their level of proficiency might be very different from someone who speaks two languages fluently.
However, we can say that a significant portion of the world's population is multilingual. Some estimates suggest that over half of the world's population speaks more than one language.
Here are some factors that contribute to multilingualism:
* Globalization: Increased travel, migration, and trade lead to greater exposure to other languages.
* Education: Many countries offer bilingual or multilingual education programs.
* Cultural diversity: In many countries, people from different language backgrounds live together.
* Historical factors: Some countries have had multiple languages spoken within their borders for centuries.
It's important to note that multilingualism is a complex phenomenon with many contributing factors. It's difficult to quantify the exact number of multilingual people, but it is safe to say that a significant portion of the world's population speaks more than one language.