Past Participles / Perfect Participles.
The Past Participles (Perfect Participles) ends in -ed, -t, -en, and -n.
1. The past participles of transitive verbs are used just as adjectives.
He has no hidden faults.
He looks frightened.
It was well-built house.
2. Generally the past participles of intransitive verbs are not used as adjectives before nouns. But there are exceptions, as shown in the following sentences:
He is a known killer.
They were trained dogs.
Mr. Bruce is a retired postmaster. …