Quoting libralady:

...One reason English is widely spoken around the world, is because of the British Commonwealth. English also contains many French and Latin words and words derived from French, Latin and Greek.

Honaray = Latin Honarrius
Honour = Latin Honor
Quorum = Latin, quotus
Pseudonym = Greek, pseudes
Questionnaire = French, Questionnaire

As far as I know Spanish is the fastest growing language in the world.

Quoting alameda:

Chinese, although spoken by many, is one of the most difficult to learn due to the very large amount of characters to have to remember and learn to read and write.