Etymology

As noted under ar, ME forms of the pres. pl. in er- are more likely to show derivation direct from the dominant ON variant continuing PGmc *er- (cp. OIcel 1 pl. erum, 2 pl. eruð, 3 pl. eru) than are ME ar- forms.  As remarked in OED3’s careful discussion, however, it is difficult to rule out a development of ME er- < ar- in low-stress positions.

PGmc Ancestor

*er-

Proposed ON Etymon (OIcel representative)

erum, eruð, eru 'are'
(ONP vera (2) (vb.))

Other Scandinavian Reflexes

Icel erum, eruð, eru

OE Cognate

Angl aron (WMerc earun etc.) 'are'; cp. WS, Angl sind, sindon

Phonological and morphological markers

Summary category

CC2c

Attestation

In LALME, <er-> forms (dot maps 121–2) (eLALME maps 0170005–7) are predominantly a feature of the ‘Great Scandinavian Belt’; see further ar.

Occurrences in the Gersum Corpus

WA 1, 12, 14 etc.

Bibliography

MED bēn (v.), OED be (v.), Dance ar, de Vries erum, eruð, eru, Mag. er (2), Bj-L. være, Seebold es-, Orel *wesanan (I), Kroonen *wesan- (1), AEW earon, DOE bēon