Seemed is the past participle of seem.
The past participle of "seem" is "seemed."
The past tense of "seem" is "seemed," and the present participle is "seeming."
The past participle of "do" is "done." The past participle of "have" is "had."
The past participle of am is been. Not does not have a past participle
The past tense of "have" is "had," and the past participle is also "had."
The principal parts of verbs are typically the base form (infinitive), past tense, past participle, and present participle.
Participles often end with '-ed', '-en', or '-ing'. There are several other common participle suffixes, but I can not recall them off the top of my head. The past participle is, I believe, "seemed."
The word foreswore does not seem to exist. The word is forswore which is the past participle of forswear meaning to "make a serious decision to stop doing something"
The past participle of am is been. Not does not have a past participle
The past participle of "do" is "done." The past participle of "have" is "had."
The past tense of "have" is "had," and the past participle is also "had."
The past and past participle for "buy" is "bought."
Being is the present participle. The past participle is been.
The past participle is thought.
Eating is the present participle; eaten is the past participle.
The past participle of the verb "to knife" may be an adjective. It is knifed (stabbed with a knife).The present participle (knifing) does not seem to be used as an adjective.
"Did" is the past and "done" is the past participle.
The past participle is had.