8. Predicate Adjectives A predicate adjective will always connect with a linking verb to add further conditions to a clause. Common predicate adjectives include any form of "be," such as is, was ...

If it doesn't make sense as a participle in a clause ... in the second pair of examples because most past participles have passive meanings when they are used as adjectives.

Note that cruel in the above example is an adjective describing behaviour so the progressive form is used with it. We can use an adverbial participle clause to express reason or cause as an ...