τι να συμπεράνει/συμπεραίνει
I've come across the phrase "δεν ήξερε τι να συμπεράνει". Because I know the verb as συμπεραίνω, I would have thought it should be συμπεραίνει. Is the spelling without the iota an alternative/mistake/different form/different verb? Many thanks!

Question

Answer

It's the same verb.  "να συμπεράνει"  is the subjunctive Aorist tense of "συμπεραίνει". "συμπεραίνει" is in the indicative Present.