Learn Turkish: Biz üç doktoruz, siz iki mühendissiniz. - We are three doctors, you are two engineers.

In English, we add an 's' to make a noun plural after a number. But in Turkish, whenever you use a number (like üç or iki) before a noun, the noun must stay strictly singular. You should never say üç doktorlar or iki mühendisler.

What do the endings on doktoruz and mühendissiniz mean?

Turkish doesn't have separate words for "am", "is", or "are". Instead, it attaches a personal suffix to the end of the noun. The -uz on doktoruz means "we are", matching the pronoun biz. The -siniz on mühendissiniz means "you are", matching the plural pronoun siz.

Why do the personal endings use different vowels (-uz vs -siniz)?

This is 4-way vowel harmony in action. The suffix changes its vowel to match the last vowel of the root word. Since doktor has an 'o', its suffix gets a 'u' (-uz). Because mühendis has an 'i', its suffix gets an 'i' (-siniz).

Do I have to include the pronouns biz and siz at the start?