Middle English word ai comes from Proto-Indo-European *h₂ekʷeh₂, Proto-Indo-European *h₂ékʷeh₂ (Water.), Proto-Indo-European *h₂eyu-, Proto-Indo-European *h₂óyu (Long time, lifetime.), Proto-Indo-European *oiw-, Proto-Germanic *agwjō
| Dictionary entry | Language | Definition |
|---|---|---|
| *h₂ekʷeh₂ | Proto-Indo-European (ine-pro) | |
| *h₂ékʷeh₂ | Proto-Indo-European (ine-pro) | Water. |
| *h₂eyu- | Proto-Indo-European (ine-pro) | |
| *h₂óyu | Proto-Indo-European (ine-pro) | Long time, lifetime. |
| *oiw- | Proto-Indo-European (ine-pro) | |
| *agwjō | Proto-Germanic (gem-pro) | |
| *aiw- | Proto-Germanic (gem-pro) | |
| *awjō | Proto-Germanic (gem-pro) | A floodplain; meadow. Island. |
| *aiwiz | Proto-Germanic (gem-pro) | |
| ey | Old Norse (non) | Island. |
| aye | Middle English (enm) |