The simple past is collected.
The past tense of collect is collected.
collect
If you meant what is collect in past tense, It is collected.
The past perfect tense is had collected.
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.