underwent
v.v. to experience something, especially a change, a medical treatment, or a difficult process.
v. to experience or be subjected to something, typically a process that is unpleasant, necessary, or transformative. The past tense of 'undergo'.
The old building underwent a complete renovation last year.
The patient underwent several tests before the doctors could confirm the diagnosis and start the treatment.
The aerospace industry underwent a period of rapid consolidation as smaller firms merged to survive the rising costs of research and development.
Transitive verb — always takes a direct object. As the past tense form, it does not take an auxiliary 'did' in affirmative statements.
He was underwent surgeryHe underwent surgeryLearners often treat 'underwent' as a passive participle; it is an active past tense verb.