Participle is one of nonfinite forms of verbs. There are two basic types of participles in English (Participle I – Ving and Participle II equal to 3rd verb form V3). But Participle I has additional forms (Present Passive, Perfect, Perfect Passive) expressed by auxiliary verbs to have and to be in required tenses. Older Black Speech dialects had the same principle of forming participles or denying them at all. For BlackSpeech.ru site new system was invented. Instead of auxiliary verbs every type of participle have got it's own suffix. But that system was inconsistent and still copying English grammar, that's why it was changed again for Nûrlâm.
There are 4 grammatical forms of participles made by combination of tense (Present and Past/Perfect) and voice (Active and Passive). Each type of participles can be used in adjectival and adverbial phrase or clause. Each of 4 types has it's own suffix with tense marked differently from verbs, which is a feature of fusional language.
Participles agree with action of main verb in grammatical tense. If action described by the participle was finished before the main verb, then suffix of Perfect form is used; if it was simultaneous with main verb or continued after it; then present form of participle is used even if the verb itself is in past tense.
Tolkien wrote that ending -at considered earlier an infinitive's suffix is more like a participle, but given translation of durbat is “constraining”, thus closer to gerund, see article gerundive for more information. Gerundive may be translated as future participle in languages which have it.
In colloquial speech participles also have category of number expressed by the standard plural suffix. It's added according to rules for declension class, after adding participle suffix to the verb root.
Participles may take the following role in the sentence: predicative (part of complex predicate with verb “kulat” (to be) to express passive voice), adjectival or adverbial phrase. Active participles are not used as predicative, passive participles are extremely rarely used as adverbials (specially in colloquial speech). Because the participle system of Nûrlâm differs from majority of European languages, some examples do not have exact translation into them and other constructions are used instead.
|Nazgum kulâ orskag zil
|The ring is being stolen now
|Nazgum kuzâ orskag shi fugh(tîl)
|The ring was being stolen at (last) night
|Nazgum kuzâ orskaga ârshik
|The ring was stolen yesterday1)
|Nagzum kulâ orskaga
|The ring is stolen!
|Uruk akrug mag lûmpuzâ
|Orc drinking too much have fallen
|Tanorkuz yakum urukob matug
|He took the weapon of dying orc
|Nazgum orskag audâ Nazgûlûr
|The ring being stolen belongs to Nazgûl
|Gund ghîrag arnirzi golugob kâtû latu urun
|Stones being desired by Elvish king lie under the mountain = The stones, that Elvish king desires, lie under the mountain
|Uruk akruga mag kâtuzâ zîgin
|There was lying a too much drunk orc
|Golugum doguga mak maudakob kubâ dûmbat
|The elf killed many (of) our warriors will be executed
|Shogurm akraga thrakuzâ hûrurm urukûr
|The potion been drunk brought courage for the orcs
|Goi dulaga kubâ krutumbat
|The destroyed city will be rebuilt = The city that was destroyed is to be rebuilt
|Uruk ukhâ lashug ash laush
|Orc walks singing a song
|Shor shîkuzâ skoirug tala kîfum
|Eagle shrieked flying over the nest
|Uruk lashâ ash laush dûmbag
|Orc is singing a song being executed
|Nazgum throgâ narthakurm tupag krûru
|The ring grants invisibility being put on finger
|Uruk lûmpuzâ akruga mag
|Orc fell having drunk too much
|Lûg bhanubâ tug shaduga za goi
|Dragon will leave only having destroyed the city
|Shogurm thrakuzâ hûrurm urukûr akraga
|The potion brought courage for the orcs having been drunk
|Uruk lûmpâ la akaga ash gothirzi
|Orc is falling after having been stabbed by an enemy
Black Speech may lack many verbal adjectives in its lexicon, so active present participles are frequent. For example, use “pushdug” (stinking) instead of some translation of “stinky”.