In Early Modern English, is "beest" subjunctive or dialectal?

Question

I am looking for better ways to translate between German and English, and I prefer Early Modern Engliſh, as a mode of speech, but mainly in written form, and I found out the other day that the Southern-Ængliſc "biſt" had survived into Middle Engliſh and Early Modern Engliſh.

I am curious, was "beest" subjunctive in Early-Modern-Engiſh, or dialectal, or both? I assume that the southern dialects (which evolved into such as the dialects of Yorkshire) preserved the word in use-common, as the north spread "are," and the North, or others, adopted "beest" and other "be" conjugations as use in subjunctive form, or to just completely replace "are."

Lastly, is it pronounced [biʔɛst] or [bist]. I assume it is either [biʔɛst] or [beʔɛst~beʔest].

If I am correct in my assumption, then I shall spell it "beëst"

Answer 1

A look at the current Dutch forms:
Present tense

Ik ben I am

Jij bent / ben jij You are (informal, singular)

Hij, zij is He, she is Dutch for Beginners

and West Frisian :

second-person singular present of wêze   

Do bist in baarch.‎ ― You are a pig.wiktionary

There is clearly no clue as to the Middle or Early Modern English pronunciation of beest from the modern cousin languages. There are two rather different vowels in those languages. Even the fact the word is spelt with a double "e" does not give much of a clue as to how it was pronounced. The subjunctive traditionally used an "e", which suggests an "e" sound, rather than an "i". The Middle-Early Modern English periods saw sound changes.Wikipedia. The "ee" in "beest" may have shifted from "e" to "i", but as the word no longer exists, there is nothing certain.

The form "beest" does seem subjunctive as the indicative in Early Modern English seemed constant from Middle English as :

am
art
is Wikipedia

But as most of the written evidence is from Southern England other forms may have existed. Yes, maybe in Yorkshire, which certainly did not have a southern dialect spoken there. The form "beest" would be consistent from Old English (be) through to Modern English, such as the records exist.Eger Journal of English Studies

Answer 2

It seems "beest" could be either an indicative or a subjunctive form.

There has been variation in the use of "be" forms as indicative vs. subjunctive forms. As described in Quuxplusone's answer to the question "Why “the powers that be”?", the word "be" could be used as an indicative form (especially in the plural) in the time of Shakespeare, so it's certainly not the case that finite verb forms starting with "be/be-" were always subjunctive.

The OED says of forms like "beest":

Historically, these continue indicative forms, but apparently at least some early modern English texts prefer beest (rather than art) in syntactic environments that otherwise favour use of the subjunctive such as conditional clauses

As far as I can tell, the original subjunctive form would have been be, with no -(e)st suffix: Wiktionary says Old English used bēo for the singular of all persons in the present subjuctive, and that Middle English used be.

In the past tense, the history of the forms wert and wast seems to be similarly complicated. The OED says

In Old English the 2nd singular past subjunctive of this verb (in common with all strong verbs) is not formally distinct from either the 2nd singular past indicative (as it would be for a weak verb) or from the 1st and 3rd singular past subjunctive; in its later history it continues to be problematic as a formal category. This section illustrates use of the 2nd singular in syntactic environments that typically trigger use of the past subjunctive; it is not entirely certain to what extent these should be regarded as subjunctive forms.