Here's why:
* Number of speakers: It has over 1.1 billion native speakers, making it the language spoken by the largest number of people in the world.
* Official language: It's the official language of China, Taiwan, Singapore, and several other countries.
* Regional dialects: While considered one language, Mandarin has many regional dialects, making it even more widely spoken.
However, if you're looking at the number of people who speak a language as a second language, English is the most spoken language in the world.