There are about five thousand languages in the world, and the one with the most speakers is Mandarin, with about six hundred and fifty million speakers. English has around three hundred and fifty million speakers.
The most common surname in the world is Chang of whom there are about three hundred and fifty million. Smith is the most common English surname: there are around eighty thousand in England and Wales, and an estimated two million, three hundred and eighty two thousand five hundred and nine in the United States.
Some languages are more complex than others. Tillamook, the North American Indian language has the most prefixes with thirty. Eskimo uses sixty three forms of the present tense and simple nouns have as many as two hundred and fifty inflections. English has between one hundred and ninety four and two hundred and fourteen irregular verbs depending on what you define as an irregular verb.
The largest dictionary in the worlds is the Oxford English Dictionary, which has twenty volumes, twenty one thousand seven hundred and twenty eight pages, two hundred and ninety thousand five hundred main entries, and around fifty nine million words. It lists the definitions of around six hundred and fifteen thousand words. The Webster’s International Dictionary, the American equivalent of the Oxford English Dictionary, list four hundred and fifty thousand words. Though in both cases, technical and scientific terms would add millions more. Altogether about two hundred thousand English words are in common use.