Learn Turkish: Mutfaktaki musluğu tesisatçıya tamir ettiriyoruz. - We are having the plumber repair the faucet in the kitchen.

The base verb is tamir etmek (to repair). To make it causative (to have someone repair), we add the causative suffix -DIr to the verb root et. Because et ends in a voiceless consonant (t), the suffix becomes -tir, giving us tamir ettirmek. Finally, we add the present continuous -iyor and the 'we' ending -uz.

Why does the plumber take the dative case (tesisatçıya) if he is the one doing the work?

With causative verbs, if the original action already takes a direct object (like repairing a faucet), the person you get to do the work is put into the dative case (-e/-a). The direct object itself (musluğu) stays in the accusative case. So grammatically, it is like saying 'We are causing the faucet-repair TO the plumber.'

What is the -ki doing at the end of mutfaktaki?

The suffix -ki acts like an adjective maker, usually meaning 'the one which is'. Here, it is attached to the locative case mutfakta (in the kitchen) to create mutfaktaki (the one in the kitchen). Placed before musluğu, it tells us exactly which faucet is being repaired.

Why does musluk (faucet) change to musluğu here?