Learn Turkish: Sınav ne zaman?

In Turkish, the present tense 'is' is often invisible! While there are personal suffixes for 'I am' or 'you are', the 'it is' ending (which is -dır or -dir) is frequently dropped in everyday conversation. So, Sınav ne zaman? is perfectly complete on its own.

Why doesn't the question word go at the beginning, like in English?

In Turkish, you usually don't move a question word to the front of the sentence. Instead, ne zaman sits exactly where the answer will go. Since the answer (like 'tomorrow' or 'on Monday') would act as the main information at the end of the sentence, the question word goes there too.

What is the difference between asking ne zaman and saat kaçta?

Ne zaman is a general 'when' and the answer could be a day, a month, or a time. If you want to know the specific hour on the clock (like 'at 2:00 PM'), you would instead ask Sınav saat kaçta? (At what time is the exam?).