The former Manchester City captain has been critical of his teammates at times this season.
But he told Die Welt: "From a sporting point of view, things are going well, but we still need to improve in many aspects. That's why they bought me. The coach told me to pass on my experience to the boys. Even if everything doesn't work perfectly yet due to the language, I can convey certain things to my young teammates just with my behavior.
"Barcelona trusts La Masía players. There are also foreigners like me who provide stability. The club has recently lost personalities, such as Lionel Messi, who marked an era. Success will not come overnight, it is a process always in collaboration with the fans.
"It's a completely new challenge. After seven years at Manchester City with Pep Guardiola, I thought it was important to get out of my comfort zone again. Not only on a football level, but also on a personal level."