2nd singular present inverted doe je

Goeman, A. (1992b): Voorbeelden van Paardekooper z’n vaste aansluiting: werkwoordsuffigering in enclise bij monosyllabische werkwoorden 2e p. enk., in: Bennis, H. en J. de Vries (red.): De Binnenbouw van het Nederlands. Een bundel artikelen voor P. C. Paardekooper, Dordrecht, Foris, 95-106. ●Examples of Paardekooper’s tight connection: verbal affixation in enclitic position to monosyllabic verbs; 2nd person singular●
[on postverbal 2nd person singular enclitic pronouns and their verbal endings; also a chapter in my
1999 book]
here (zipped)

Map 1 Enclitic suffix doe+...-je (Goeman 1992b)

It is shown that enclitic forms, if transcribed meticulously, give much information on the form of the pronoun and on the verbal suffix as well.
I try to explain all 2nd person verbal suffix forms of the verb
doen that exist in the dialect of the Netherlands. Data are from recent fieldwork (GTRProject).
The verb
doen is chosen because monosyllabic verbs with their enclitics give crucial information on the form and the presence of Comp-agreement.
In general, the expression of Comp-agreement is the combination of monosyllabic verbal form + enclitic.
In an earlier study I could (De Visser & Goeman 1979, 238-240) show that the dialects of Oost-Vlaanderen have a hidden -
e suffix for 1st singular and 1st and 2nd plural persons, retraceable only by a lengthening of the vowel of the subordinator da , the same lengthening is also occuring in the verb's stemvowel when followed by a clitic pronoun.
- That Eastern Flemish vowel length is not phonologically relevant, is not a valid objection, because the neutralization of this contrast is occurring in well defined distributional positions (Taeldeman 1978, 40).

We must take for granted an -
e suffix in enclitic position for Noord-Holland, Zeeland and for northeastern provinces of the Netherlands; these are dialects with ingwaeonic features. This suffix is relatively old, because it is also occurring in Middle Low German and in Old English.
Most of the attestations in Middle Low German are in the enclitic position of 1st person plural, but that is a consequence of the sort of text in charters, where direct address of 2nd person plural seldom occurs. On the origin of this -
e suffix are opinions divided.
It may stem from original -
et, and from -en as well. In the last case it is provable for Old High German that 1st plural person -e(n) is an optative (Braune 1975, 260).
Old English has enclitic -
e in 1st and 2nd persons plural; as have Dutch northeastern dialects. According to Sievers (1898, 194-195) the verbal forms show then an optative form in the indicative, as shown by the stem vowel of have.
Sievers traces the chronological development as follows; of old, the verbs on -
mi and the contracted verbs have adhortative plural suffixes ending in -n (present, optative and preteritum, preterito-presents included).
Then the optative influenced in its adhortative function the present indicative:
we habbadh - haebbe we, the last form showing an optative vowel in a form with present function. After that, there was an expansion over other indicative forms. The process has run farthest in Anglian.
The western ingwaeonic dialects show most correspondences with Kent.