Chaucer was as incomprehensible to [Shakespeare’s contemporaries] as he is to us, but we can still comprehend Shakespeare with a little effort, and the literature since then with correspondingly less effort.
1 Whan that Aprill with his shoures soote
When April with its sweet-smelling showers
2 The droghte of March hath perced to the roote,
Has pierced the drought of March to the root,
3 And bathed every veyne in swich licour
And bathed every vein (of the plants) in such liquid
4 Of which vertu engendred is the flour;
By which power the flower is created;
5 Whan Zephirus eek with his sweete breeth
When the West Wind also with its sweet breath,
6 Inspired hath in every holt and heeth
In every wood and field has breathed life into
7 The tendre croppes, and the yonge sonne
The tender new leaves, and the young sun
8 Hath in the Ram his half cours yronne,
Has run half its course in Aries,
There are some odd words, such as the pronoun hir, which has been replaced with their in modern English, but overall, the general shape of the language isn’t that hard for us to figure out, even 627 years later. We teach it to 12th graders, for goodness’ sake–it’s not rocket science (though, honestly, we teach that, too, in some classes)!
Shakespeare, by contrast, wrote in Modern English. Here’s Shakespeare, completely as he wrote the lines:
Let me not to the marriage of true minds
Admit impediments. Love is not love
Which alters when it alteration finds,
Or bends with the remover to remove:
O no; it is an ever-fixed mark,
That looks on tempests, and is never shaken;
It is the star to every wandering bark,
Whose worth’s unknown, although his height be taken.
Love’s not Time’s fool, though rosy lips and cheeks
Within his bending sickle’s compass come;
Love alters not with his brief hours and weeks,
But bears it out even to the edge of doom.
If this be error and upon me proved,
I never writ, nor no man ever loved.