Breakdown of Она всегда прощает друга за ложь.
она
she / it (for a feminine noun)
друг
friend
всегда
always
за
for (in exchange for)
Questions & Answers about Она всегда прощает друга за ложь.
Why does ложь not change its ending after the preposition за?
The preposition за here indicates the reason for the action (what she is forgiving him for) and requires the accusative case. However, ложь (lie) is a feminine noun ending in a soft sign. For this specific group of nouns, the accusative form is exactly the same as the nominative form.
Why is the word for friend written as друга and not друг?
The verb прощать (to forgive) takes a direct object in the accusative case. Because друг is an animate (living) masculine noun, its accusative form takes the -а ending, making it look identical to the genitive case.
Why do we use the imperfective verb прощает instead of its perfective counterpart?
The adverb всегда (always) tells us that this is a habitual, repeated action. In Russian, actions that happen regularly or repeatedly must use the imperfective aspect.
Why doesn't the Russian sentence include a word for 'her' before друга?
In Russian, possessive pronouns are often dropped when the context makes it obvious. Since the subject is doing the action to her own friend, it is naturally understood. You could add своего (her own), but leaving it out sounds perfectly natural.