The Netherlands international spent just one season at Newcastle where he scored 11 goals in 40 games.
Wijnaldum, 25, is looking forward to working with the eccentric Jurgen Klopp and cannot wait to witness the German's passion for the game.
"(He seems) a great man - from the outside - because I don’t know how he works yet and I have to work with him.
"(But) I always love to watch him, his passion as a trainer, I like how he enjoys the game. He gives something back to the group (with his passion) so I look forward to working with him".
Klopp has also expressed his excitement to work with his new signing.
"I think he can be a great player for us," said the manager.
"He has already shown some really good moments in his career but the most exciting and important thing for me and my staff is that there is still so much extra to come from him.
"When I talked to him I could tell that he knows we have to work together to get this level out of him to all be successful for the team".