Translation

証明する / 証言する / 証拠となる

Meaning

Attest means to state, show, or serve as evidence that something is true. It is formal and often appears with to: the results attest to the problem.

Examples

• 多くの目撃者が、その警報が鳴ったことを証言できます。
  Several witnesses can attest that the alarm sounded.
• 売上の伸びは、その製品への強い需要を示しています。
  The sales figures attest to strong demand for the product.