Learn Farsi: هر سال باید لطف او را جبران کنم؛ برایش هدیه می‌خرم. - Every year I must make up for his kindness; I buy a gift for him.

برایش (barâyash) is a combination of the preposition برای (barâye), meaning "for", and the pronominal enclitic ـَش (-ash), meaning "him", "her", or "it". Instead of saying برای او (barâye u), Farsi speakers frequently attach these short pronoun endings directly to prepositions. Notice that the final "e" sound of barâye merges with the enclitic to sound like "barây-ash".

Why does the verb jobrân konam not have the mi- prefix, while mi-kharam does?

The first verb, جبران کنم (jobrân konam), follows باید (bâyad), meaning "must". In Farsi, verbs following bâyad must be in the subjunctive mood to show obligation or uncertainty, taking a be- prefix instead of mi-. However, because جبران کردن is a compound verb using کردن (kardan - to do), we just use the present stem کنـ (kon-) with the personal ending ـَم (-am) and typically drop the be- prefix entirely. The second verb, می‌خرم (mi-kharam - I buy), is a stated fact happening regularly, so it keeps the present indicative mi- prefix.

Why is the direct object marker râ (را) used here after lotf-e u?

We use را (râ) when the direct object of the sentence is specific or definite. Here, you aren't just making up for some random kindness, but specifically "his kindness" (لطف او - lotf-e u). Adding a possessive pronoun like "his" automatically makes a noun specific, so we must put right after it.