Complex sentence: During the 2011--12 season, Janmark made his pro debut in Sweden's Elitserien, appearing in 18 games for AIK Stockholm, and was the team captain for the club's U20 team.
Split into simpler sentences: During the 2011--12 season, Janmark made his pro debut in Sweden's Elitserien, appearing in 18 games for AIK Stockholm. Janmark also was the team captain for the club's U20 team.