Yes it's the past participle of encourage.
It's also the simple past tense of encourage. Regular verbs have the same simple past and past participle.
The past participle is "encouraged"
"Encouraged" is the simple past and past participle of the verb "encourage".
The verb encourage has the present participle encouraging, which as an adjective can have the adverb form encouragingly.
Being is the present participle. The past participle is been.
The past participle of "do" is "done." The past participle of "have" is "had."
The present participle of "sow" is "sowing," and the past participle is "sown."
The past participle of "begin" is "begun" and the present participle is "beginning."
The present participle of beat is beating, and the past participle is beaten.
The past participle of "am not" is "have not been."
No, the word store is not a participle. The present participle is storing. The past participle is stored.
The present participle is swelling. The past participle is swelled.
The past participle is proceeded. The present participle is proceeding.