Linking verbs connect the subject of a sentence to a noun, pronoun, or adjective that renames or describes the subject. They do not show an action.
Examples:
* She is a doctor. ("doctor" renames "she")
* The sky is blue. ("blue" describes "sky")
Transitive verbs take a direct object, which receives the action of the verb.
Examples:
* She wrote a letter. ("letter" is the direct object)
* He kicked the ball. ("ball" is the direct object)
Intransitive verbs do not take a direct object.
Examples:
* The baby slept.
* The birds flew.