Learn Turkish: O adamlar yorgun, sen hastasın. - Those men are tired, you are sick.

In Turkish, when pointing words like o (that/those) or bu (this/these) are used right before a noun, they never take the plural ending -lar or -ler. The plural is only marked once, on the noun itself (adamlar). So, O adamlar means "Those men".

Why is there no "are" ending attached to yorgun (tired)?

For the third person ("he", "she", "it", or "they"), Turkish often leaves out the "to be" ending entirely in everyday speech. Saying O adamlar yorgun is a perfectly complete phrase and means "Those men are tired".

How do we get the ending -sın in hastasın?

The base word is hasta (sick). To say "you are", we add the "to be" suffix for "you", which is -sin. Because of 4-way vowel harmony, we look at the last vowel in hasta, which is "a". The harmony rules say that "a" or "ı" is followed by "ı", so the suffix becomes -sın.

Since -sın already means "you are", is the word sen necessary?