Katozuka
To speak woth someone. Using words. You speak your language. One language, maybe several. You communicate with other humans and make yourself understood. You understand others when they speak. If they speak a language you understand, ofcourse. To speak is a wonderful thing, That's something you learn in an early age.
Responsibility is when you're finally old enough. Old enough to stay home alone. Old enough to babysit your siblings, old enough to go to a party, old enough to live by yourself. You have to take care of yourself and respect others. Then you show responsibility.