Tell how the italicized noun clause is used.

'Whatever you tell me' shall remain our secret.

subject

subject complement

direct object

object of the preposition

The phrase inside the clause is a direct object. Direct objects in sentence construction answer the questions "what?" and "for whom?." In this sentence, the question "what shall remain our secret?" is the appropriate tone to ask to determine what the direct object of the sentence is. And the answer to the question is the phrase, "whatever you tell me."