I have a book that claims けど is a conjunction (接続詞), yet another book that I have claims that it is a particle (助詞).
Seems it doesn't seem to make sense if けど is both a conjunction and a particle, I was wondering who is right?
けど is a conjunction.It is not a particle. In conjunction with… …と関連［接続］して； …と合同［連絡］して, …とともに. and けど is also 接助・終助.
adverbial particles 副詞的小詞 《on, in, out, over, off など》.