From the ide- stem of idő (“time”) + -i (adjective-forming suffix). Compare idén (“ this year”).
idei (not comparable)
| Inflection (stem in -e-, front unrounded harmony) | ||
|---|---|---|
| singular | plural | |
| nominative | idei | ideiek |
| accusative | ideit | ideieket |
| dative | ideinek | ideieknek |
| instrumental | ideivel | ideiekkel |
| causal-final | ideiért | ideiekért |
| translative | ideivé | ideiekké |
| terminative | ideiig | ideiekig |
| essive-formal | ideiként | ideiekként |
| essive-modal | — | — |
| inessive | ideiben | ideiekben |
| superessive | idein | ideieken |
| adessive | ideinél | ideieknél |
| illative | ideibe | ideiekbe |
| sublative | ideire | ideiekre |
| allative | ideihez | ideiekhez |
| elative | ideiből | ideiekből |
| delative | ideiről | ideiekről |
| ablative | ideitől | ideiektől |
| non-attributive possessive - singular |
ideié | ideieké |
| non-attributive possessive - plural |
ideiéi | ideiekéi |
idei
idei