question: infinitive without to after verb to be

Hi everyone,
I need to know if my following sentence is correct or not and why. Considering the use of a verb as an object in a sentence, can we use it as the object of the verb to be in such a way?

“His perfect hobby is to dance.”
In this case I imagine dancing would be correct, but can I still use to dance by meaning the action of dancing instead of the noun?

Normally when discussing a verb as an activity the gerund is used. This form for your sentence would be dancing (without to).

i agree with you. Hobby is a noun and so its counterpart in the tag, predicate, must also be a noun. In details, a gerund. We can use to infinitive or bare infinitive alone after to be to express an activity or a purpose, don’t we? God bless me. Wish mister micawby wouldn’t come over here. Omg i can see him somewhere nearby. Run for yr life. Oops, my life.