They finally opened the door for him.
In this first example, the verb “opened” is an action verb since it is describing a specific action performed by someone.
The teacher challenged her.
In this second example, the verb “challenged” is also an action verb since it is describing an action.
Linking verbs, on the other hand, do not describe an action but link subject and verb by providing more information about the subject. An example of a linking verb is “The cake smells good”. In this case the verb “smells” is connecting subject and verb.
The answer to your question is today.
1) I like to run. (functions as a direct object)
2) I wanted to cook dinner for my parents. (functions as a direct object)
3) To fly an airplane is a dream of mine. (functions as a subject)
4) I cannot believe you knew to put out grits to attract ants! (functions as a direct object)
5) The fair is the place to go. (tells us which place)
Hope I was able to help. :)