Which language is most used in the world?

The most used language in the world depends on how you measure it.

By number of native speakers:

* Mandarin Chinese is the most spoken language with over 1 billion native speakers.

By total number of speakers (native and non-native):

* English is the most spoken language with around 1.5 billion speakers. This is because English is widely used as a second language, especially in business, education, and technology.

So, while Mandarin Chinese has the most native speakers, English is the most widely spoken language overall.