You have spotted a certain class of English verbs called copular or linking verbs. They link the subject to a predicate complement, either an equivalent noun (called a predicate nominative)
John is my son.
or a descriptive modifier (called a predicate adjective in case the modifier is an adjective).
John is strong.
As you've noted, the predicate modifier might well be a participle, which is just a verb form that finds service in a sentence in a role other than a verb. The fact that the modifier is a participle is not significant. The syntactic structure is the same for all modifiers:
The sauce tastes burned.
The sauce tastes delicious.
Copular verbs are verbs of being, seeming, sensing, and a few others. Copular verbs stand in contrast to dynamic verbs, which carry an action to an object:
John hit my son.
This differs form the copular sentence, which makes John and son equivalent. Here the verb carries out an action to son. Dynamic verbs cannot govern following noun modifiers like adjectives. You cannot say
*John hit strong.
The following modifiers of dynamic verbs modify the verb, and so must be adverbs:
John hit strongly.