Already is not a verb so does not have a past participle form.
The past participle of "already" is "already." "Already" is an adverb and does not have a different form for the past participle.
Thought is already the past participle of "think".
The past participle for "broken" is also "broken."
"Talked" is already the past participle, or past indicative, of "talk". "Talked" as such does not have a past participle, because it is not an infinitive form of a verb.
The past participle of "sat" is "sat." For example, "I have sat here for hours."
The past participle of prepare is (have or has) prepared. For example, "I have already prepared tonight's supper."
"Had" is already the past participle of "have".
Tried is already in past participle form. It is the past participle of try.
Jumped is already the past participle of jump.
Consumed is already in past participle form. It is the past participle of consume.
Thought is already the past participle of "think".
Imagined is the past participle of imagine.
The past participle for "broken" is also "broken."
The past participle of submit is submitted
It is already in past tense.
Laid is already the past tense and past participle of lay.
Listened is already in past participle form. It is the past tense and past participle of listen.
Caught is already the past tense and past participle of the verb catch.