testify
v.v. to speak the truth in a court of law or a formal meeting. You do this to provide evidence or proof about what happened.
v. to give evidence as a witness in a court of law or before a judicial body. Often used figuratively to serve as evidence or proof of a particular fact or situation.
The witness agreed to testify against the suspect.
Several former employees were called to testify during the investigation into the company's financial records.
The crumbling ruins of the ancient temple testify to the immense power and architectural sophistication of a civilization that vanished centuries ago.
PIE word *tréyes From Middle English testifien, borrowed from Old French testifier, from Latin testificārī (“to bear witness”), from testis (“a witness”) + facere (“to make”). See -fy.
The verb is intransitive when used in a legal context, often followed by 'against' or 'on behalf of'. When used figuratively to mean 'serve as proof', it is followed by the preposition 'to'.
he testified the truthhe testified to the truthWhen 'testify' means to serve as evidence, it requires the preposition 'to' before the noun.