Verb-endings in older English
Up to and beyond the time of Shakespeare, and for much later in certain forms of English, our language used different forms of words (inflections) to show the jobs they were doing in sentences. This was most true of verbs (though see also pronouns (archaic)).
As in most European languages, and many outside Europe, the ending of a verb alters depending on who (or what) is its subject. These changes only apply to the present tense, after very early times.
In the present tense, the speaker (the first person singular) uses the simple, or base, form of the verb. When we say that the person(s) to whom we are speaking (the second person) is doing something, there is a difference depending on how many there are. More than one of 'you' (the second person plural) uses the base form. A singular 'you' (only one), which was communicated in older forms of English by the pronoun 'thou', had a verb ending in -est. The third person singular (the person we are talking about, 'he' or 'she') has a verb ending in -eth. All the plurals, 'we', 'you' and 'they' use the base form.
So the verb 'to go' looked like this:
|he, she or it||goeth|
There are irregularities, of course (the English language is full of them), in this neat pattern. The three primary verbs 'to be', 'to have' and 'to do', and the common verb 'to say' look like this:
|to be||to do||to have||to say|
|1st person sing:||I||am||do||have||say|
|2nd person sing:||thou||art||dost||hast||sayest, saist|
|3rd person sing:||he/she/it||is||doth||hath||saith, sayeth|
|All persons, plural||are||do||have||say|
Be aware that in Shakespeare and his contemporaries these endings may often be contracted. -eth can become -th, particularly after a vowel,. The common second person singular of 'to say' for example is sayest - sometimes pronounced, and written, as a monosyllable, saist. (You should be able to see that in the table above, doth is already a contraction for doeth.) In some dialogue, the question equivalent to the modern 'Do you say so?' is realised as Saistow?, with an inverted V + S order, a contracted verb inflection, and a colloquial reduction of the 'th-' of 'thou' to 't-'.