What are examples of infinitives used as a noun, adjective, or adverb?

see below

An infinitive is a verb form

to + verb

• Used as Noun:

Ex: To obey is better than sacrifice. ---used as subject in the sentence

• Used as Adjective:

Ex: I need a place to study . --- used as modifier for "place". (ask: What kind of place do I need? ans: a place "to study")

• Used as Adverb:

Ex: She invited her friends to go shopping. --- used as modifier for the verb "invited".