Which language has the largest vocabulary?

Answer

A popular answer is that it is English, because it is a language of Germanic origin, with a strong Romance influence on the vocabulary. However, it is not that simple. The claim that the English vocabulary exceeded the billion in April 2006 is nonsense: it is a number counted by the English Oxford Corpus, which is actually a basic tool for dictionaries and gets ALL words in English language books, web forums, magazines: also abbreviations, technical slang, proper names, place names, youth language, fantasy language (everything from Harry Potter)…

Vocabulary depends not only on the thickness of the dictionaries, but also on usage by individuals. You can speak a language with surprisingly few words: a gifted six-year-old speaks an average of 1500 words in any language community, a starting college student 5000, someone with higher education about 8000. All much less than would fit in a pocket dictionary. The degree of mastery also differs, of course: you understand more words than you use. An average standard dictionary, in any language, can easily reach 60,000 words. Dictionaries are printed (or online) for a reason: they are far above the average individual upper limit for individuals’ passive vocabulary. In any language. If English speakers had such a large vocabulary, they would hardly need small explanatory dictionaries.

If your question can be translated into which language describes the most words in dictionaries, then you arrive at English and French, which, firstly, already have a long period of language description (and can therefore absorb many archaic words) and secondly, still strongly evolve (neologisms, new scientific jargon, words from subcultures). Counts are difficult to compare, because there are also differences in counting: what counts as a separate word in one dictionary, counts in another language as a variant of another word, or as a regional language, or as a loanword, or as a compound . Moreover, the same concepts are split in one language and contracted in another: melting pot / creuset or rayon de soleil / sunray. And the real champions may be the agglutinative languages, which make endless ‘hottentot tent exhibition words’ such as Hungarian, Finnish, Turkish, Korean.

The 1989 Oxford English Dictionary (20 volumes) had 171,476 English words plus some 9,500 derived words, but was broad: at least 47,156 words of which were definitely archaic, a larger proportion may be. The Académie Française counted about 100,000 words in the Trésor de la Langue Française. Given the differences in counting, they are definitely not far apart.

To make the long answer short:

• Comparative vocabulary counts are impracticable and meaningless.
• On average, people master 8,000 words actively, and twice that passively.
• The thickest dictionaries are English and French, but they also charge generously.