Ri-verbs - Origin

Origin

Historically, róa and snúa belonged to the seventh class of strong verbs, which was the only class of verbs in Germanic that had retained the reduplication inherited from the Proto-Indo-European perfect aspect. In Old Norse, the verb sá ("to sow") also belonged to this group, but it has become weak in Icelandic. The past tense of these three verbs from Proto-Germanic was as follows:

• *rōaną ("to row") - *rerō ("I rowed")
• *snōaną ("to turn") - *seznō ("I turned")
• *sēaną ("to sow") - *sezō ("I sowed")

Originally, all class 7 verbs showed this reduplication. In most verbs containing -ē- in the stem, this changed to -ō- through ablaut, which was common to all strong verbs. The change from s- to z- was a form of Grammatischer Wechsel and was due to Verner's law, since the reduplicating prefix was originally unaccented. In Old Norse, this -z- was rhotacized to -r-, creating the following Old Norse forms:

• róa ("to row") - røra, rera ("I rowed")
• snúa ("to turn") - snøra, snera ("I turned")
• sá ("to sow" < *sáa) - søra, sera ("I sowed")

The forms with ø were older and resulted from u-umlaut caused by word-final -ō, which became -u in Old Norse before disappearing just as it did in feminine nouns. Following this, the verbs adopted the endings of weak verbs in the past tense, with -a, -ir, -i in the first, second and third person singular past, and later the original vowel e was restored. The verbs gróa and gnúa (núa in modern Icelandic) were adapted to the forms of róa and snúa by analogy, although they did not begin with s- or r- (their past tenses in Germanic were *gegrō and presumably *gegnō).

In modern Icelandic, the first person singular ending was replaced by -i in all weak verbs, and the ri-verbs followed suit. The verb sá then eventually became weak, reducing the number of ri-verbs to the current four.