Learn Turkish: Şu doksan adam yaşlı mı?

In Turkish, nouns that come right after a number always stay in the singular form. Since the word doksan (ninety) already tells us there is more than one, adding the plural suffix -lar to adam is unnecessary.

Does the word doksan (ninety) come from the word for nine?

Yes! Just like 'nine' and 'ninety' in English, some Turkish numbers by tens are built on the base numbers. Dokuz is nine, and doksan is ninety. Another similar example is sekiz (eight) and seksen (eighty).

The English translation says 'those,' so why does the Turkish sentence use the singular şu instead of şunlar?

When demonstrative words like bu (this/these), şu (that/those), or o (that/those over there) are used as adjectives right in front of a noun, they never take a plural ending. They only become plural (bunlar, şunlar, onlar) when they stand alone to replace a noun.

Why does the yes/no question particle take the form mı in this sentence?