Where does “-au” come from?
-au (Welsh) comes from Middle Welsh -eu, from Old Welsh -ou, from Proto-Brythonic -ow, from Proto-Celtic -owes.
-au (Welsh): -s
Ancestry of “-au”, step by step
| Step | Language | Word | Meaning |
|---|
| 1 | Middle Welsh | -eu | — |
| 2 | Old Welsh | -ou | — |
| 3 | Proto-Brythonic | -ow | — |
| 4 | Proto-Celtic | -owes | — |