I frequently see claims to the effect that English has by far the largest vocabulary of all languages, given that it has over 170,000 words theoretically in current use (although something over 98% of all written English texts employ a vocabulary of less than 20,000 words).
However, the comparisons I’ve seen of the vocabulary size of English with other languages all invoke competitors where, IMHO, English is punching significantly below its weight. Yes, I’m not surprised that English may be approximately twice as big, vocabulary-wise, as Spanish or German or French, say. But Spanish and German and French are not what spring to my mind when I think of languages with large vocabularies.
The reasons commonly adduced to explain the unusually large size of English vocabulary generally include the following:
major influence from multiple language families, especially its fundamental mix of Germanic and classical tongues;
hundreds of years of exposure to and borrowing from other languages due to Anglophone political and cultural influence worldwide;
a large number of native speakers and second-language speakers;
absence of formal academic oversight of its linguistic development.
French and German certainly aren’t comparable to English in these respects, but it’s not clear to me that other languages aren’t. In particular, I would think that Hindi/Urdu would have many similar factors favoring large vocabulary size. E.g., it has two separate major linguistic influences from extremely prolific ancient languages: Persian (itself a hybrid of two distinct linguistic streams from different families, Arabic and Middle Persian) and Sanskrit (also hybridized, from proto-Indo-Aryan and Dravidian and other South Asian language families). Hindi/Urdu has also borrowed like crazy from more recent linguistic sources, and has a huge number of speakers, many of whom enrich its content with words from other languages.
However, I can’t seem to find an authoritative source on the size of Hindi/Urdu vocabulary (although I’ve seen it stated without cite or explanation as 120,000 words), nor can I find any explicit comparison between English and Hindi/Urdu vocabulary size. Anybody got the Straight Dope?