Focus on the pronunciation of testify
English definition of “testify”
/ˈtestɪfaɪ/ verb [I or T]
› LAW to make a formal statement about something, especially in a court of law: testify that He testified that the store owner had lied when he applied for the state license. The senator testified to the House Committee on Financial Services.
› to say that something is true: Managing people is not easy, as many new managers can testify.