The verb in the example is "to paint". The principle parts of this verb are "paint", "painted" and "painted". The second and third principle parts happen to be the same, as they are for most English verbs.
However, that similarity does not occur in every English verb. For example, the principle parts of "to take" are "take", "took", "taken".
- She painted this picture.
- She took this picture.
This sentence uses the second principle part -- the past tense form. The word is used as a verb, has a tense, and has no auxiliary.
- She has painted this picture.
- She has taken this picture.
This sentence uses the third principle part -- the participle form. The word is used as part of a complete verb that includes the auxiliary "has". The complete verb is in the present tense and the perfect aspect.
The version that uses the verb "to take" cannot be mistaken for the past tense form -- "taken" looks and sounds nothing like "took". For the version that uses "to paint", it is only the fact that there is an auxiliary verb that indicates "painted" is the participle form.
By the way, this is not a passive voice construction. Passive voice uses the auxiliary "to be" instead of "to have". For example, "the picture was taken" or "the picture will be painted".
Participles can be used as a part of a complete verb, but they can also be used as modifiers. When they are modifiers, they are not combined with auxiliaries.
In general, participles that are alone come before the noun, as in "the painted picture". Participial phrases, however, tend to follow the noun:
- The picture painted by Karen is now in a museum.
- The picture taken by Karen is now in a museum.
The phrase "painted by Karen" does not have a tense, does not form a predicate, and does not have a subject. Instead, it behaves like an adjective and answers the question "which picture?" There is a verb in this sentence, but that verb is "is". The subject of "is" is "picture".
Prepositional phrases can do the same sort of job. Consider:
Your comment includes an example sentence that has bad grammar:
- The picture was painted by Karen is now in a museum.
Here's the problem: "Was painted" is a complete verb. It has a tense, it forms a predicate, and it needs a subject. "Is" is also a complete verb, possessing tense and forming a predicate and needing a subject. Unfortunately, there's only one subject available, and it can't satisfy both predicates.
There are a few ways to fix that problem. One way is to remove "was" and let "painted by Karen" act as a modifier. Another way is to give "was painted by Karen" its own subject, such as "The picture that was painted by Karen is now in a museum." Yet another way is to join the two predicates with a conjunction, so that the one subject can satisfy the resulting compound: "The picture was painted by Karen and is now in a museum."
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.
Best Answer
As a learner I would say, in your two sentences the verb is the linking verb is. After linking verbs you can use either an adjective or a noun phrase. The important thing is that a past participle can play three main different roles:
Moreover, I think it is important to mention that the superlative and comparative forms for such adjectives are constructed using most and more.