Learn Turkish: Mülakat için adayın duruşunu değerlendirmem lazım. - I need to evaluate the candidate's posture for the interview.

It comes from the verb durmak (to stand). By adding the manner suffix -uş, it becomes the noun duruş, which translates literally to 'way of standing', meaning 'posture' or 'stance'.

What are all the suffixes at the end of duruşunu?

After duruş (posture), we add -u (his/her, making it 'the candidate's posture'). Then we need the buffer letter -n-, and finally the accusative case -u because this specific posture is the direct object of the evaluation.

Why does aday (candidate) have the -ın suffix?

Because it's the owner in a possessive relationship. Adayın duruşu means 'the candidate's posture'. Aday takes the genitive (owner) suffix -ın, and the thing they own (duruş) takes the possessive suffix -u.

How does the grammar in değerlendirmem lazım work?

To say 'I need to do something' in Turkish, you say 'My doing something is necessary'. Here, we take değerlendirmek (to evaluate), change it to the short verbal noun değerlendirme, add the 'my' suffix -m, and follow it with lazım (necessary).