In the sentence, The hummingbird is the only bird that can fly backward, the verb is either "is" or "can fly"

Question

I cannot determine what the subordinate clause is.

Answer 1

Which of these clauses cannot stand alone?

The hummingbird is the only bird

that can fly backward,

Answer 2

The Garfield of a great app You go truculent t 6r Gy5djg fly