Happened.
Happen is not a participle. It is the simple present tense. The present participle is happening, and the past participle is happened.
The three simple tenses of a verb are past, present, and future. The past tense refers to actions that have already happened, the present tense refers to actions that are currently happening, and the future tense refers to actions that will happen.
things that happen in past time that is called history
Simple past is used:to describe something that happened at a definite time in the past.They went to Spain. (last year, in 1999, for Christmas).to describe something which could not happen or is unlikely to happen in the present or future;If I owned a Ferrari I would be happy.
The past simple of "have" is "had."
The simple past is had.
Past simple and simple past are both the same thing. They are both the past tense of a verb.
The simple past tense is climbed.
The simple past and past participle are both 'had'.
The simple past and past participle are both brought.
The simple past tense is studied.
"Listened" is the past simple of "listen" as well as the past participle.