how can you tell the difference between an infinitive phrase functioning as a direct object and an infinitive phrase functioning as an adverb?

Question

anonymous · Answer

An infinitive phrase can function as an adverb when it explains WHY the subject of a sentence makes an action. For example: Sarah is taking an environmental science class TO UNDERSTAND THE CHANGES OF THE ENVIRONMENT. Here, the infinitive phrase, "to understand the changes of the environment", explains why Sarah takes the class.

As a direct object, an infinitive phrase will function as a noun for a verb. For example: John hopes TO GAIN RECOGNITION FROM HIS PEERS by leading the school's football team to victory. Here, the infinitive phrase, "to gain recognition from his peers", is the hope of John.

anonymous · Answer

So, with the sentence "Teach me how to dance." or "Tell me what to do." are these functioning as adverbs since they are explaining why the speaker wants to know something?

anonymous · Answer

No, it would be a direct object because it's explaining what the speaker wants to do.