How doth Shakespeare decide which verbs end in "-th"?

When reading Shakespeare or the King James Version of the Bible or any other English text from that period, some verbs end in “-th” or “-st” while others don’t. This page explains the grammatical basis, namely that only third person singular verbs should end in “-th” and second person singular verbs should end in “-st”. However, these endings are used only part of the time even in those cases. Was there any rule or convention for determining when these endings were used, or was it random?
PS: Could a mod please fix the thread title? Thank you.

The English language was changing in Shakespeare’s time and so to a degree, it was all in flux. Add to that the fact that Shakespeare was a poet and regularly took license not only with all kinds of grammatical “rules” but also with syntax in the construction of his verse.

The KJV is considerably more staid in its grammar and syntax, despite also being verse.

The -th for the third-person singular changed into -s in present-day English: “He loveth” became “He loves”. So they knew when to do it much in the same way as you know when to add -s to verbs: by hearing it many times, and generalising the practice to all but some irregular exceptions (like “He is” and “He has”).

To put the two posts above together, both “he hath” and “he has” would have sounded “right” to Shakespeare, much the same way that “either” can be (eye-thur) or (ee-thur) to us. In his day, “has” (and -s in general) was spreading at the expense of “hath,” so “hath” may have nuances for his audience (class, region, old-fashioned). And sometimes the choice of [-s] or [-th] isn’t Shakesey so much as the editor of the First Folio or even the Folger Shakespeare Library.

What he did NOT do is the modern practice of sticking a -th on the end of verbs whenever he wanted sound old-fashioned, e.g. “Goeth to the store and getteth me some pop-tarts.” That would have sounded as stupid to him as it does to us.

He also didn’t rhyme “doth” with “moth,” one of my pet peeves. (Cite:

Spelling in title changed from “Skaespeare” to “Shakespeare.”

Maybe the OP fell aspleep.


Extreme example in Taming of the Shrew I.i:

“Does” and “doth” are exactly the same word in meaning, person and number; the choice of different conjugation endings for it in different instances seems to be a purely aesthetic decision.

Maybe Saekspere hathed the same keyeborad I doth.

Or he just guesthed.