Manager Carlo Ancelotti has been keen to bolster the Toffees' midfield in the summer transfer window and has now recruited one of his prime targets.
"I hope, like I have done in my entire career, I contribute with my performances together with my team-mates and that I put in some great games, great performances and win important things.
"It is a club with a rich history in the Premier League, has real ambition and then there is 'Professor' Ancelotti.
"It is the size of the club and the name of the coach which means you don't think twice about coming to Everton."
"A strong part of my game is marking and the desire going in to win absolutely every ball," he said.
"I believe with my desire I can put in really good performances to win the fans over. I received a lot of messages from Everton fans and that made me really happy and confident in the work I can do here."