vt.

1. 證實，證明[（+to）]
   attest the truth of somebody's words

   證明某人的話屬實

2. 作為……的證明；表明[+（that）]
   His achievements attest his devotion to science.

   他的成就是他對科學的獻身精神的明證。

3. 使宣誓

vi.

1. 證實，證明[（+to）]
   Her success attests to her ability.

   她的成功表明她有能力。

v.

1. provide or serve as clear evidence of.
2. declare that something exists or is the case.