Learn Farsi: اسبشان بیرون نیست.

In Farsi, you can show possession using attached endings called enclitics. Here, the ending -eshân means "their". When you attach it directly to the word asb (horse), you get asbeshân (their horse).

How do you pronounce the connection between asb and the ending?

When adding these plural endings to a word that ends in a consonant like asb, we use a short "e" sound as a bridge. So, it is pronounced asb-eshân, not just "asb-shân". This short "e" is not written as a separate letter in the Farsi alphabet.

Does asbeshân mean one horse or multiple horses?

It means just one horse. The ending -eshân tells us that there are multiple owners ("their"), but the base word asb is singular. If the owners had multiple horses, you would make "horse" plural first, resulting in asbhâ-yeshân (their horses).

Why does the sentence end with nist?

Farsi sentences typically follow a Subject-Object-Verb word order. The verb nist (is not) goes at the very end of the sentence. The literal translation is "Their horse outside is not."