Some examples of archaic language used by John Keats include:
* Thee: This archaic pronoun was used in the second person singular case, and was typically used to address someone in a formal or respectful manner.
* Thou: This archaic pronoun was used in the second person singular case, and was typically used to address someone in a familiar or intimate manner.
* Thy: This archaic possessive pronoun was used in the second person singular case, and was typically used to refer to something belonging to someone.
* Hath: This archaic verb was used in the third person singular case, and was typically used to indicate possession or ownership.
* Didst: This archaic verb was used in the second person singular case, and was typically used to indicate past tense.
In addition to these examples, Keats also used a number of other archaic words and phrases in his poetry, such as "yclept," "erstwhile," and "methinks." By using these words and phrases, Keats was able to create a unique and distinctive style that set his poetry apart from that of his contemporaries.