Although the average English speaker has a vocabulary of about 4000 words, Shakespeare had about 29,000 different words published in his plays. Shakespeare invented many new words by playing with language and many of these have become part of our language today such as:

amazement
gloomy
zany
equivocal
barefaced
critical
leapfrog
obscene
submerged
fretful
hurry
lonely

just to name a few.

All of these words can make for difficult reading, but once you adjust, it becomes much easier. Coleridge said of Shakespeare 'I believe Shakespeare was not a whit more intelligible in his own day than he is now to an educated man.' It's true Coleridge was talking two centuries ago, but he was also talking two centuries after Shakespeare.