Learn Farsi: عینک استاد تمیز نیست. - The professor's glasses are not clean.

The Ezafe is the "e" sound connecting عینک (glasses) and استاد (professor), pronounced as aynak-e ostād. In Farsi script, this short "e" vowel is usually not written out, but you must say it to show that the glasses belong to the professor.

Why is the word order عینک استاد ("glasses professor") instead of the other way around?

When showing possession in Farsi, the thing that is owned always comes first, followed by the Ezafe particle, and then the owner comes last. So, عینک استاد essentially translates to "the glasses of the professor".

Why does the Farsi sentence use the singular verb نیست (is not) when the English translation uses "are not" for glasses?

In Farsi, the word for glasses (عینک) is a singular noun because it refers to a single object. In English, we treat "glasses" as a plural noun. Because it is singular in Farsi, it must take the singular verb نیست (is not) rather than a plural verb.

Is نیست just the negative version of است (is)?

Yes! While most verbs are made negative by adding a simple prefix like نـ, the "to be" verb است (ast) changes its whole form to نیست (nist) to mean "is not".