The simple past tense is 'designed'.
Designed is both the simple past and the past participle of 'design'.
The past participle is "designed".
had designed
designed
The past simple of "invent" is "invented." It is formed by adding "-ed" to the base verb. For example, "She invented a new gadget last year."
Designed is both the simple past and the past participle of 'design'.
things that happen in past time that is called history
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.
Had is the past of have. A past simple sentence:I had a headache this morning
Designed is the past tense of design.