I'm working with linking, transitive and intransitive verbs. For this sentence, do I need to write it as a statement? I think it is a linking verb. Intransitive?

"What is the most popular song in the country this week?"

"What is the most popular song in the country this week?"

That is a question.

The verb, "is," is a linking verb.

Is it also intransitive?

All linking verbs are intransitive -- they cannot have direct objects following them.

Can What be a subject? Or is song the subject?

In this sentence, "What" is the subject and "song" is the predicate noun (also called predicate nominative).

http://grammar.ccc.commnet.edu/grammar/index2.htm

To determine whether a verb is linking, transitive, or intransitive, let's break down the sentence:

"What is the most popular song in the country this week?"

First, let's identify the verb in the sentence. The verb in this sentence is "is."

Now, let's consider the characteristics of each type of verb:

1. Linking Verbs: Linking verbs connect the subject of a sentence to a subject complement, which either renames or describes the subject. Common linking verbs include "is," "am," "are," "was," and "were."

2. Transitive Verbs: Transitive verbs require a direct object to complete their meaning. The action of the verb is transferred from the subject to the object. In this sentence, there is no direct object following the verb "is."

3. Intransitive Verbs: Intransitive verbs do not require a direct object. They express action or a state of being without the need for an object.

Based on the information provided, the verb "is" in the sentence is a linking verb. It connects the subject "the most popular song in the country this week" to the complement "what."

As for the sentence structure, it is a question, so you would write it as an interrogative sentence, not a statement.