As a noun:
* The lawyer presented compelling testimony from the witness.
* The victim's testimony was crucial to the case.
* The defendant's testimony contradicted the evidence presented by the prosecution.
* The doctor's testimony helped to prove the patient's injuries.
* The historical documents provided valuable testimony about the past.
As a verb:
* The witness testified about what they saw.
* The defendant refused to testify in his own defense.
* She testified before the committee about the need for reform.
In a figurative sense:
* The ruined castle stood as a stark testimony to the power of time.
* Her success is a testimony to her hard work and dedication.
Remember that "testimony" can refer to both spoken and written statements, and it can be used in a variety of contexts, from legal proceedings to historical research to personal narratives.