The passive voice is formed from past active participle and the auxiliary verb شدن (šodan). The future passive participle of a verb is formed from the infinitive in passive voice and the suffix ی (i). Future passive participles literally mean “going to, about to” but depending on the context, they can create words that convey “due to”, “necessary to”, “suitable to”, “worthy of”, “able to”, etc.

Infinitive Future Passive Participle
شستن
šostan
to wash
شسته‌شدنی
šostešodani
able to be washed
پاک کردن
pâk kardan
to clean
پاک‌شدنی
pâkšodani
able to be cleaned

Negative form

The negative form of future passive participle is formed by prefixing ن (na-) to شدن

Infinitive Future Passive Participle
شستن
šostan
to wash
شسته‌نشدنی
šostenašodani
unable to be washed
پاک کردن
pâk kardan
to clean
پاک‌نشدنی
pâknašodani
unable to be cleaned