Rich is an adjective, it doesn't have a past tense.
The past participle form of the word "use" is "used."
"Use" is a regular verb; therefore, its past participle is "used".
Rich is not a verb, rich is an adjective.richen is a verb, richened is the past tense.
The word "run" is a word that can be used in both past and present tenses. For example, "I ran" (past) and "I run" (present).
When "out" is used as a verb the past tense is outed.
The word amount does not have a past tense.Alternative AnswerThe word "amount" has a past tense when it is used as a verb. When used as a verb, it means "to total" or "to be the same as". The past tense of this form is amounted.
The word "past" is primarily a noun. It can also be used as an adjective, an adverb and as a preposition.
Used
The word "bound" is the most commonly used past tense of "bind".The word binded is used, but is the non-standard form.
The past tense is memoed.
Yes, the past tense of need is needed.
"Hopped" is a word used in past tense.