William Shakespeare is famous for using many words in his plays which were new introductions to the English language. According to Shakespeare Online:
The English language owes a great debt to Shakespeare. He invented over 1700 of our common words by changing nouns into verbs, changing verbs into adjectives, connecting words never before used together, adding prefixes and suffixes, and devising words wholly original.
However, other sources claim that many of the words often thought to have been coined by Shakespeare were in fact already in use before his time. From Merriam-Webster:
It should be noted that at no point did the editors of the OED say "We have X entries for which Shakespeare is the earliest known user; therefore he invented X number of words." [...] As lexicographers have gained access to electronic databases the number of words for which Shakespeare is the first recorded source has shrunk dramatically. Yet we still are regularly informed that "Shakespeare coined the word X" in formats ranging from Internet lists to academic papers. So in the spirit of lexical clarity—or, if you prefer, punctiliousness—we present you with a list of words that people love to say were invented by Shakespeare.
They were not.
On the other hand, I remember reading that some words which appeared in Shakespeare plays caused problems for the typesetters when the plays first went to print, due to their unfamiliarity. So it does seem to be definitely true that he invented at least some words.
While it must by now be impossible to tell in many cases whether or not a given word in one of Shakespeare's plays had ever been used in English before him, I'm hoping that it will be possible to come up with at least a ball-park figure, somewhere between none and 1700.
Roughly how many of the words in Shakespeare's plays were new additions to the English language?