Learn Farsi: پنج الماس بزرگ اینجا استخراج شد.

In Farsi, when the subject is plural but inanimate (like objects or concepts, such as almās / diamond), the verb is almost always conjugated in the third-person singular form. So, even though there are five diamonds, we use the singular shod instead of the plural shodand.

Why isn't the word for diamond pluralized as almās-hā since there are five of them?

In Farsi, whenever you use a number before a noun (like panj for five), the noun must stay in its singular form. You don't add the plural marker -hā to the noun if you've just stated its exact quantity.

How does the passive voice work here with the compound verb?

The active verb for "to extract" is estekhrāj kardan (literally "to do extraction"). To make a compound verb passive, you swap the helper verb kardan (to do/make) for shodan (to become). So, the simple past passive is just the noun part (estekhrāj) followed by the simple past of shodan, which is shod.

How do we connect the words for "diamond" and "large" when speaking?

You connect them using an Ezafe (a short "-e" sound). It is spoken as almās-e bozorg. Remember that in Farsi, the adjective (bozorg) comes after the noun (almās), and the Ezafe acts like a glue linking them together.