The appropriate conjunction to fill in the blank is "If". It is used to express a hypothetical condition.
The appropriate conjunction to fill in the blank is "If". A conjunction is a word that joins phrases, clauses, sentences, or words together.
The sentence should read: "If I were a bird, I would immediately fly to you." The conjunction "If" is used to express a hypothetical condition, indicating that the speaker is imagining what would happen if they were a bird.