communication mode

In the class, we learn how to call person of different relations. I like to use Wechat and message for my friends, family or someone else. If i sent for my family, my best friends, i can use casual calling for them. When i talking with them, it can improve my expression, writing and have enough time to express my idea for them. When i can't express clearly, i can use message, writing maybe will better to understand for them. If i have some important things that should have a evident, i can type or write down. Two persons know each other not a long time, of course they can use different kinds of communication channels.