Learn Turkish: Kuşatma boyunca halk aç kalmış olsa gerek. - The people must have stayed hungry during the siege.

The structure -mIş olsa gerek is used to make strong logical deductions about the past. It combines the reported past suffix -mIş with olsa (if it is) and gerek (necessary/probable). Literally, it means something like "it must be the case that they stayed," which perfectly translates to "must have stayed" in English.

Why use aç kalmış (stayed hungry) instead of just saying they were hungry?

In Turkish, the collocation aç kalmak (literally "to remain hungry") is the standard way to express "going hungry" or enduring starvation over a period of time. Just saying they "were hungry" would sound more like the temporary, everyday feeling you get before a normal meal, rather than the severe lack of food during a siege.

Can boyunca be used for physical places, or is it only for time like in kuşatma boyunca?

Boyunca works for both time and space! When used with time or events (like kuşatma, yıl, gün), it means "during" or "throughout." When used with physical places (like yol boyunca or nehir boyunca), it means "along" (along the road, along the river).

Since halk translates to "the people" (plural), why doesn't the verb have a plural suffix like kalmışlar?