Where does “do-” come from?
do- (Manx) comes from Old Irish do-, from Proto-Celtic dus-, from Proto-Indo-European dus-, from Proto-Indo-European dēwǝ- — to fail, be behind, be lacking.
do- (Manx): non-, un-
Ancestry of “do-”, step by step
| Step | Language | Word | Meaning |
|---|
| 1 | Old Irish | do- | impossible, extremely difficult; ill, evil;... |
| 2 | Proto-Celtic | dus- | bad |
| 3 | Proto-Indo-European | dus- | bad |
| 4 | Proto-Indo-European | dēwǝ- | to fail, be behind, be lacking |