1º χ?ισέα > χ?ισῆ
2º ἀ?γυ?έα > ἀ?γυ?ᾶ
3º χαλκέα > χαλκῆ
4º σιδη?έα > σιδη?ῆ
In all of them the contraction is ε+α and some end with an η while other with α.
I understand the 1º and the 3º contract to η because the preceding sound is nor ?, nor ε nor ι, and adjectives cannot have impure α.
The 2º contracts to α because it is preceded by ?.
But what about the 4º? Why after ? there's an η? Is this a typing mistake in my booklet? If it isn't, how can I tell when the contraction that took place after a ? sound between an ε and an α gave ῆ and when gave ᾶ?
Thanks in advance
