The simple past and past participle are both welcomed.
The past participle for the word "welcome" is "welcomed."
The past participle form of the verb "welcome" is "welcomed."
The past participle of the word "have" is "had."
The past participle of the word "do" is "done."
The past participle of the word "pick" is "picked".
The past participle of the word "finish" is "finished."
The past participle form of the verb "welcome" is "welcomed."
The past participle of the word "have" is "had."
The past participle of the word "do" is "done."
The past participle of the word "pick" is "picked".
The past participle of the word "finish" is "finished."
The past participle of the word "Find" is the word "Found."
The past participle of the word 'fall' is 'fallen'.
The past participle of the word "swore" is "sworn."
The word "invited" is the past participle of invite.
The past participle of the word "hop" is "hopped."
Yes, it can be an adjective. It is the past tense and past participle of the verb "welcome" which is also a noun.
The word "it" does not have a past participle as it is a pronoun. It is only verbs that have a past participle.