Learn Farsi: او یک عکس جدید در شبکه‌های اجتماعی پست کرده است. - She has posted a new photo on social networks.

In compound verbs, only the second part (the helper verb) changes. The first part, پست (post), stays exactly the same. We change کردن (to do/make) into its Present Perfect form for he/she, which is کرده است. Together, they form پست کرده است (has posted).

Why is the letter ی added between شبکه‌ها (networks) and اجتماعی (social)?

That is the ezafe connector, which links a noun to its adjective. The plural word شبکه‌ها ends in the vowel a (from the plural suffix ها). When a word ends in a vowel, the ezafe is pronounced -ye and must be written with the letter ی to bridge the two sounds.

The English translation says on social networks, but the Farsi sentence uses در. Why?

Prepositions often do not translate word-for-word. While English speakers talk about being on the internet or on social media, Farsi treats these digital spaces as containers, so you use در (in) instead.

Is the word پست just the English word post?

Yes! Farsi frequently borrows modern tech and internet words directly from English. Since Farsi needs verbs to follow its own grammar rules, it pairs the borrowed noun پست with the Farsi helper verb کردن to create the new compound verb پست کردن (to post).