Original: How I Met Your Mothers other main characters are Lily Aldrin (Alyson Hannigan), Marshall Eriksen (Jason Segel), Robin Scherbatsky (Cobie Smulders), and Barney Stinson (Neil Patrick Harris).
Simplified: Other characters and friends of Ted are Marshall Eriksen (Jason Segel), Robin Scherbatsky (Cobie Smulders), Barney Stinson (Neil Patrick Harris), and Lily Aldrin (Alyson Hannigan).