American English
/ˈtʰɛs.təˌfaɪ/
3 syllables · Stress the first syllable.
to speak in court or in an official investigation about what you know, usually after promising to tell the truth
Practice out loudto speak in court or in an official investigation about what you know, usually after promising to tell the truth
The witness testified in court.
She testified against her former boss.
This word is usually used in court or another official setting. For a normal personal story, use tell or say.
testify under oath · testify before a committee · testify for the defense
testify in court
testify against someone
to state formally that something is true, based on what you know or have experienced
Her experience testifies to the value of good training.
He testified that the report was accurate.
testify to the truth · testify to the importance of something
testify to something
testify that something is true
to show clearly that something is true or that something happened
The ruins testify to the city's long history.
Their success testifies to years of hard work.
testify to the damage · testify to someone's skill
something testifies to something
to give evidence after promising to tell the truth
The witness testified under oath.
to give evidence that may harm someone in a legal case
He agreed to testify against the suspect.
to give evidence in support of someone
Several colleagues testified on her behalf.
The y changes to i before -es and -ed: testifies, testified. Before -ing, keep the y: testifying.