Learn Farsi: این آثار تاریخی باارزش توسط موزه خریداری می‌گردد. - These valuable historical works are purchased by the museum.

می‌گردد comes from the verb گردیدن (gardidan), which is a formal, written equivalent of شدن (shodan). In journalistic or formal texts, you will often see گردیدن (or another verb, گشتن) used as the auxiliary verb to form the passive voice. Here, خریداری می‌گردد means exactly the same thing as the everyday خریداری می‌شود (is purchased).

The subject is آثار (works), which is plural. Why is the verb می‌گردد singular instead of the plural می‌گردند?

In Farsi, inanimate plural subjects like آثار usually take a singular verb. While you could technically use the plural می‌گردند to personify the items or give them special importance, using the singular form is the standard grammatical rule for non-living things.

What is the word آثار and why doesn't it have a regular Farsi plural suffix like -ها?

آثار is the Arabic broken plural of the word اثر (asar, meaning work, trace, or monument). Farsi borrowed many Arabic plurals, and while you might occasionally see اثرها, the broken plural آثار is much more common and sounds more natural in formal contexts like this one.

How does توسط work in this passive sentence?

توسط (tavasot-e) translates to 'by means of' or 'through'. In Farsi, the passive voice usually drops the person or thing doing the action. When you do need to specify who performs the action (like the museum in this sentence), is the standard formal way to introduce them, similar to 'by' in English.