en- bumal pristu sbrɨt -ër he- water cleanliness obtain -3sg.neut
water obtains cleanliness ≃ water gives cleanliness'En', in fact the pronoun 'he', serves to typecast a neuter noun - temporarily, it is of the masculine gender and thus by pretend has a separate nominative. It is more reduced than it would be if they were different constituents - in fact, /ɘ̆ⁿ'bʊmɑl pristu sbrɨ'ter/ would be a fair rendering of the phrase here, whereas /e:n bʊmɑl/ would be the usual form if the words occurred in sequence. There is never any elements between the pronoun and the noun in this construction - adjectives and other attributes precede it, unlike what would happen normally.
However, secondary cases alter the situation a bit - definite neuter nouns do not require to be preceded by 'en', although if they are subjects of a transitive sentence with a non-neuter object, they are slightly likely to have it. Partitive neuter nouns are very unusual as transitive subjects. Possessed nouns tend to be objects. Secondary subjects tend to take 'en', whereas reciprocal objects almost never do.
Some object markings in fact seem to be perceived as demoting the object to oblique status, and thus reducing the verb to intransitivity, thus letting the neuter ~transitive subject stand in the unmarked case. However, the animacy of the object also affects whether the transitivity is understood to have been affected - generally speaking, the more animate the object, the less detransitivized the verb. Thus, an inanimate masculine or feminine object in the partitive might permit for the neuter subject to stand in the absolutive/nominative case, a neuter object in the partitive almost certainly permits this to happen. The reciprocal object marking on an object does this as well, as does the negative congruence - which in most dialects is partitive marking on non-subjects that are not marked for anything else.
Finally, in a number of fossilized expressions, the listener is assumed to know which participant is considered the subject, which the object, i.e. the tongue twister
skarmu darnu skɨrna, marnu sgarmu kɨrnir, 'storm shook roof, heat curdles milk'
Many of the possible transpositions of consonants in this phrase lead to rather explicitly sexual readings.
As always in the description of Bryatesle, we end up with a lot of vaguely probabilistic usage patterns, rather than hard and fast rules.