The 28-year-old winger admits he still holds the Old Trafford club in his heart following a six-year stay but insists he is enjoying life in Spain and playing for Real Madrid.
The 28-year-old Portugal captain has been strenuously linked with a return to Old Trafford this summer where he spent six-years before moving to the Berbabeu for a world record 80 million pounds in 2009.
Ronaldo won eight trophies and scored over 100 goals in his time with United and while conceding he is still emotionally attached to the club, he is happy with life in Spain.
"I miss English football," said Ronaldo, speaking at a promotional event in Singapore. "For me, it was one of the best years in my career when I was there in Manchester United. Everyone knows that it is a club that is still in my heart and I really, really miss.
"But now my life is in Spain. I am enjoying playing there too."
Ronaldo wouldn't rule out a return to Manchester.
"Part of my life is there, but in the future we never know," Ronaldo said. "I am really, really happy in the Spanish league."