Auxiliary verb SKILLE

(Note: infininitve 'SKILLA' or 'SKILLE' is a reconstruction based on other verbs; it does not appear in the OLB.)
Although the following N-European varieties are all obviously cognates, they are not all used in the same way:

• shall - English (mostly deontic modality; in past tense also epistemic)
• sille - Frisian (mostly future tense; English: will)
• zullen - Dutch (mostly future tense)
• sollen - German (mostly deontic modality; also epistemic?)
• skola - Swedish (presens all 'skall'; preteritum all 'skulle'; perfect 'skolat'; can also mean to school)

FRYAS*	English	German	Dutch*	Frisian*
IK SKIL	all conjug.:	ich soll	ik zal	ik sil
THV SKILST	shall	du sollst	jij zult	do silst
ER SKIL		er soll	hij zal	hy sil
WI SKILUN		wir sollen	plur.:	plur.:
I SKILE**		ihr sollt	zullen	sille
HJA SKILUN		sie sollen

* see notes about personal pronouns and formal/polite 2nd person in next post/ **only once in samples

FRYAS	English	German	Dutch	Frisian
IK SKOL(D(E))	all conjug.:	ich sollte	sing.:	ik soe
-	should	du solltest	zou	do soest
ER SKOLDE*		er sollte		hy soe
WI SKOLDON		wir sollten	plur.:	plur.:
I SKOLDE**		ihr solltet	zouden	soene(n)
HJA SKOLDE***		sie sollten

* SKOLD in 4 out of 31 cases
** only once
*** SKOLDON in 3 out of 17 cases

In the samples, some of the verbs most often supported by SKILUN are:

• 16x WERTHA (become, be: passive voice)
• 14x KVMA (come)
• 8x HÀVA (have) 
• 8x WÉSA (be: active voice)
• 6x LÉTA (let)
• 4x BILÍWA (remain, stay; Dutch/ German: blijven/ bleiben)
• 4x NIMMA (take; Dutch/ German: nemen/ nehmen)