Reconstruction:Proto-Germanic/an

Etymology
From, but the exact formation is disputed due to the final vowel in descendants that reflect. According to Kroonen, who derives both and  from a pre-Germanic, the final vowel was lost by regular sound change but remained in compound forms, whence it was restored in some of the daughter languages. Alternative explanations for the final vowel include a fossilized suffix / of uncertain (allative?) function, as in.

Preposition

 * 1) on, upon
 * 2) onto

Adverb

 * 1) on, onto