There are minor barriers to effective communication ;like lack of communication,improper use of nonverbal communication ,timing and context as well as improper communication networks .would you please help by explaining them?

Lack of communication can be as simple as people not talking - it's a broad area. Using non verbal communication wrongly could include gestures that appear impolite, or touching a person in a way they find inappropriate. Timing and context are related to this, eg a hug could be fine in one context but wrong in another. And the wrong networks include, eg sending really important message by text.