Learn Turkish: Nüfus sayımını yarın yapacaklar. - They will do the census tomorrow.

It is derived from the verb saymak (to count). The suffix -(ı)m turns a verb into an abstract noun representing the result or act of that verb. Therefore, sayım literally means a counting or a tally.

Why are there two -ı vowels at the end of sayımını?

The phrase for census (population count) is a noun compound: nüfus + sayım + -ı (the possessive suffix linking the two nouns into nüfus sayımı). Because this compound noun is the specific direct object of the verb yapacaklar, it must take the accusative case suffix -ı. The -n- is a buffer consonant to separate them, resulting in sayımını.

Why use yapmak here instead of a more specific verb for conducting a census?

yapmak (to do / to make) is the standard and natural choice. In Turkish, it frequently acts as a light verb that pairs with abstract nouns ending in -m (like sayım, seçim or bakım) to mean to carry out or to conduct that specific action.

What is the effect of placing yarın right before the verb?