Sentence examples for eaten breakfast from inspiring English sources

The phrase "eaten breakfast" is correct and usable in written English.
It is a past participle verb phrase that describes an action that has already been completed. It can be used as a subject, object, or complement in a sentence. Example: I have already eaten breakfast. In this sentence, the phrase "eaten breakfast" acts as a verb phrase that describes the action of "eating breakfast" that has already been completed. Another example: The doctor suggested that I have already eaten breakfast before my appointment. In this sentence, "eaten breakfast" functions as the object of the verb "have" and describes the action that has already been completed.