Learn Hardcore Turkish: Akrilik boyayı karıştırırken su miktarını kontrol etmek gerekiyordu. - You needed to control the amount of water while mixing the acrylic paint.

In Turkish, when you talk about a specific or “definite” direct object, you add the accusative suffix -ı/‐i/‐u/‐ü (here -yı, due to vowel harmony and a buffer consonant). Since akrilik boya (“acrylic paint”) is definite in this context, boya becomes boyayı.

What does the suffix -ken in karıştırırken indicate?

The suffix -ken creates a temporal (time) clause meaning “while …ing.” You take the verb stem karıştır- (“to mix”), attach the buffer -ı-, then -ken, yielding karıştırırken = “while mixing.”

Why does the sentence use su miktarını instead of just su or miktar?

su miktarı literally means “amount of water.” You need both words because su specifies what you’re measuring, and miktar means “amount.” Then you add the accusative -ı on miktar (→ miktarını) to mark it as the direct object of kontrol etmek.

How does kontrol etmek gerekiyordu work? Why isn’t it just kontrol ediliyordu?

Here gerekmek (“to be necessary”) takes an infinitive: kontrol etmek (“to check/control”). Together they form “it was necessary to control…” Using kontrol ediliyordu would be the passive of kontrol etmek, but you then lose the natural gerekmek + infinitive construction. You could say kontrol edilmesi gerekiyordu, but that’s more formal or indirect.

Why is etmek used after kontrol?

Many Turkish verbs are built by combining a noun or borrowed root with etmek. kontrol is a noun (from French), so to make it a verb you say kontrol etmek (“to control/check”).

Why is gerekiyordu in the past tense?

The sentence describes a past situation (“when we were mixing paint”). To express that back-then necessity, gerekiyor (“it is necessary”) shifts to past: gerekiyordu (“it was necessary”).

Can you use the passive voice here, like akrilik boya karıştırılırken su miktarını kontrol etmek gerekiyordu?

Grammatically you can, but it sounds odd. karıştırılırken would mean “while the paint was being mixed” (agent unspecified) rather than “while you/he/she was mixing the paint.” The active karıştırırken is more natural when you want to emphasize the action you’re doing.

What’s the difference between karıştırmak and karışmak?

karıştırmak is transitive: you mix something (you do the mixing). karışmak is intransitive and can mean “to get mixed” or colloquially “to interfere.” Here we need karıştır- because you actively mix the paint.