The infinitive of いただける is いただく, the humble form of もらう/うけとる (to receive) and たべる/ のむ (to eat / to drink / to have). 私は本をいただいた。--> It means "I received the book" but we know the one who gave the book is older than "I" or is high in status / social position in general. 先生のおたくで (= 家で) ケーキとコーヒーをいただいた。(I ate / had cake and drank / had coffee in the teacher's house.) For question sentence, to ask for something, it meas like "could you please...?" ペンを貸していただけませんか。(Could you lent me your pen?) 電話番号をおしえていただけませんか。(Could you tell me your phone number?) We also use this word for something that isn't good, I mean, something bad, but with this word, we can soften the sentence like "not to be acceptable / not very good / not very delicious / not very interesting, etc". 彼女はやさしくてとてもいい人だが、彼女は料理がへただ。It's correct but saying so isn't good, then you can say 彼女の手料理はちょっといただけない。but not to her direcly, you can say so when you talk about her with other people. Note, you have to take care because the meaning can be changed depending on the situation. You have to understand the whole situation, not only this いただける. It might have other meaning but I don't remember now. I hope this was helpful.