Definitions

1. verb

past tense of ‘do’ or ‘to do’, expressing completed actions

“I did my homework last night.”

2. verb (auxiliary)

used to form the past tense or past participle of another verb

“She had eaten breakfast before leaving the house.”

3. auxiliary verb

used to form the past tense or past participle of another verb

“By the time we arrived, they had already finished the project.”

4. past participle

used to form the present perfect tense of another verb

“I have done my best to solve the problem.”