attest
v.v. to show or prove that something is true. You use this when you provide evidence or act as a witness for a fact.
v. to provide evidence for or serve as proof of something; to certify the truth of a statement or document. Often takes the preposition 'to' when indicating the subject of the testimony.
His many awards attest to his great skill.
The lawyer asked the witness to attest to the validity of the signature on the contract.
The archaeological findings in the valley attest to a sophisticated civilization that flourished long before the arrival of colonial explorers, challenging previous historical assumptions.
PIE word *tréyes Borrowed from Middle French attester, from Latin attestor (“to witness to, bear witness”), from at-, combining form of ad (“to”) + testor (“to bear witness”), from testis (“a witness”).
The verb is often intransitive when followed by 'to' ('attest to something'), but can be transitive in formal legal contexts ('attest a document').
He can attest for my character.He can attest to my character.While 'vouch' takes 'for', 'attest' typically takes 'to' when providing evidence of a quality or fact.