Hand-book of Volapük/16
THE PARTICIPLE 
The participle is a verb-adjectiv. Its ending is -öl, corresponding to -ing, -ed. It may be in the activ or passiv voice, and in any tense, tho' the patüp, petüp and potüp are the most common.
Logöl, seeing. Elogöl, having seen. Ologöl, about to see, being about to see. Palogöl, seen, being seen. Pelogöl, seen, having been seen. Pologöl, about to be seen.
It is often necessary to examin English passiv participles very carefully, to determine what tense they really signify.
The house seeri in the distance, dom palogöl in fog. The house built on a rock, dom pebumöl su klif.
If we turn the sentence into the activ form it will be clearer. The house which we see in the distance. The house which some one has built (not is building) on a rock.
There is another form of the participle, slightly differing from the future, and having the augment ö instead of o. Its meaning is that which must or ought to do something, or that which must or ought to be done.
Öbinöl, that which ought to be. Pöfinöl, to be finished. Pöks pömenodöl, errors to be corrected. Pöks pomenodöl, errors which will be corrected.