Learn Farsi: این اشخاص دیگر افکار جالب ندارند. - These individuals no longer have interesting thoughts.

The words اشخاص (individuals) and افکار (thoughts) are both Arabic broken plurals. They come from the singular words شخص (shakhs - person) and فکر (fekr - thought). They both follow the common a-C-C-â-C pattern (where C stands for the root consonants). Recognizing this pattern will help you quickly spot many Arabic plurals in Farsi!

Why does the sentence use the singular این (this) instead of the plural این‌ها (these) before اشخاص?

In Farsi, demonstrative words like این (this) and آن (that) always stay in their singular form when they come directly before a noun, even if that noun is plural. So, "these individuals" is simply این اشخاص.

I know دیگر usually means "other." Why does it mean "no longer" in this sentence?

When دیگر is used in a sentence with a negative verb (like ندارند - they do not have), it translates to "no longer" or "not anymore." The literal translation is closer to "These individuals do not have interesting thoughts anymore."

Would it be correct to use the singular verb ندارد here, since افکار (thoughts) is an inanimate plural?

No, because the subject of the sentence is اشخاص (individuals), which refers to living people. In Farsi, animate plural subjects must take a plural verb (ندارند). Even though افکار (thoughts) is an inanimate plural, it is just the object being possessed, not the subject doing the action.