Learn Turkish: Kazandığımı faize yatırabilir miyim? - Can I deposit what I earned for interest?

This is a headless relative clause. We take the verb kazanmak (to earn), add the participle suffix -dık and the possessive -ım to mean "that I earned". Because we dropped the noun it describes (like "the money that I earned"), the participle stands alone and becomes a noun itself, meaning "the thing I earned" or "what I earned".

What is the final -ı at the end of kazandığımı doing?

It is the accusative case suffix. Since "what I earned" is the specific direct object receiving the action of the verb yatırmak (to deposit), it requires the accusative case. So it breaks down as kazan (earn) + dık (participle) + ım (my) + ı (accusative).

Why does faiz (interest) take the dative suffix -e here?

In English, you might say you deposit money "for" interest, but the Turkish expression is faize yatırmak, which literally translates to depositing money "to" interest. The dative case shows the direction or purpose of the deposit.

Can you break down the suffixes in yatırabilir miyim?