VERB
說明，表示，證明（某事屬實）
To attest something or attest to something means to say, show, or prove that it is true.
例句
Police records attest to his long history of violence...
警方記錄證明他有長期從事暴力活動的前科。
I can personally attest that the cold and flu season is here...
感冒和流感季節來了，對此我有切身體會。