Transitive or Intransitive Sentence Explanation:
Transitive or intransitive sentences are two types of sentences based on the action performed by the subject of the sentence. Let's analyze the sentence "Cathy writes poetry" to determine if it is transitive or intransitive.

Transitive Sentence:
- A transitive sentence is a sentence in which the action performed by the subject is done to someone or something.
- It requires a direct object to receive the action of the verb.
- In transitive sentences, the action is transferred from the subject to the object.

Intransitive Sentence:
- An intransitive sentence is a sentence in which the action performed by the subject does not require a direct object.
- The action is not transferred to anyone or anything in intransitive sentences.
- Intransitive verbs do not require an object to complete their meaning.

Analysis of the Sentence "Cathy writes poetry":
- In the sentence "Cathy writes poetry," the verb "writes" is an intransitive verb.
- The subject "Cathy" is performing the action of writing, but there is no direct object receiving the action.
- Since there is no direct object in the sentence, it does not meet the criteria of a transitive sentence.
- Therefore, the sentence "Cathy writes poetry" is an intransitive sentence.
In conclusion, the sentence "Cathy writes poetry" is an intransitive sentence because the verb "writes" does not require a direct object to complete its meaning.