adverb
surely; I swear; upon my word
Emphatic adverbial use of the て-form of 誓う (to swear), expressing strong assertion or conviction. Often used in somewhat dramatic or old-fashioned speech.
誓って、私は無実です。
I swear I am innocent.
adverb
Used with a negative predicate to strongly deny something. Equivalent to 'absolutely not' or 'never'.
誓ってそんなことはしません。
I would never do such a thing.