Question

he is not only an artist but also an engineer​

Answer 1

Here the 2 sentences are

He is an artist

He is an engineer.

Both the sentences are connected by the conjunction Not only _but also.

Answer 2

Here both the sentences are connected.

It Is connected by the conjunction Not only, but also.

It is correlative conjunction. used to connect and emphasize 2 words or 2 phrases.

Used to list nouns or verbs, quantities or actions, events, states, etc.

 → He is not only an artist but also an engineer​

    The 2 sentences are;

      He is an artist

      He is an engineer.