* No Global Census: There's no single, reliable, and up-to-date census that tracks language data for the entire world.
* Definitions of "Language" and "Speak": What constitutes a language versus a dialect can be subjective. Also, what does it mean to "speak" a language? Fluency, understanding, or simply knowing a few words?
* Constantly Changing: Language use evolves. New languages emerge, and languages can disappear. Migration patterns also influence language distribution.
However, here are some things we can say:
* English is NOT the most spoken language: Mandarin Chinese has the most native speakers globally.
* English is WIDELY spoken: English is an official language in many countries and is used extensively in international communication, business, and education. This makes it difficult to estimate the percentage who speak ONLY other languages.
To get a better understanding, you could look at:
* Statistics on the number of native speakers of different languages.
* Data on the percentage of people who speak English as a second language in various countries.
* Research on language diversity and multilingualism.
Remember, these statistics will only provide estimates and should be interpreted with caution.