Breakdown of Ты когда-нибудь любил её?
ты
you (singular)
любить
to love, to like
её
her (acc)
когда-нибудь
ever / sometime
Questions & Answers about Ты когда-нибудь любил её?
Why does когда-нибудь mean 'ever' here instead of 'sometime'?
The particle -нибудь adds a sense of 'any' to question words. While когда-нибудь can mean 'sometime' in the future, in a question like this, it asks if the action happened at any point in the past. In English, we naturally translate this as 'ever'.
Could I use когда-то instead of когда-нибудь?
Not in this kind of question. The word когда-то means 'once' or 'formerly'—referring to a time in the past that actually happened. Because you are asking if it happened at any possible time, you need the indefinite -нибудь ending.
Why is the verb любил just in the past tense? Doesn't the English translation say 'Did you...'?
Russian doesn't use helping verbs like 'do' or 'did' to form questions. To ask 'Did you love?', you simply use the past tense of the verb, which is любил. Since it ends in -л, we also know that the person being spoken to (ты) is male.
Why is the pronoun её used here?
The verb любить (to love) takes a direct object, which means the person being loved must be in the accusative case. The word её is the accusative form of она (she).