Is there a way to know the email password of somebody else?

I suspect someone , betraying me .

Is there a way to know the email password of somebody else?
It is possible if its not complex enough or if you wrote it down. The best thing to do now is change it immediately. If any friends or ? bring up the subject or try to find out if you changed it, your suspicions might be right.
Reply:They can tell you, you can infect their PC with spyware or a keylogger and learn it, you can pretend to be them and ask for a reminder if you know all about them and can answer their security questions
Reply:Yes, ask the person who own the email account..





I mean in other way..such as asking them questions that have another questions inside.