Learn Turkish: Raporun aksine ürün kullanışsız. - Contrary to the report, the product is useless.

The word aksine acts as a postposition meaning "contrary to" or "unlike." When it follows a specific noun or a pronoun, that preceding word must take the genitive case (like the -un here). Since we are referring to a specific report, it becomes raporun aksine.

Where does the -e at the end of aksine come from?

The base word is akis (the contrary or opposite). In this grammar structure, it acts as a possessed noun taking the possessive suffix -i (which drops the second vowel in akis to make aksi), followed by the buffer letter -n-, and finally the dative case -e (to). So raporun aksine literally translates as "to the report's contrary."

Could we use tersine instead of aksine in this sentence?

Yes, you can perfectly say raporun tersine ürün kullanışsız. Both aksine and tersine are completely interchangeable when expressing "contrary to" or "unlike," and both require the genitive case on the preceding specific noun.

How is the word kullanışsız built from its root?