Every summer, I hire college students to be my interns, and I usually make my male interns teach at least one time. Since they typically haven’t taught before, I attempt to teach them how to communicate clearly.
At the foundation of preaching/teaching is the content. This is raw biblical information, theories, principles, etc. This involves the preacher/teacher correctly understand and interpret scripture. Depending on the nature of the sermon, it may involve exegesis, studying theology, or correcting integrating various principles or doctrines.
This point involves the teacher presenting biblical truths which make them clear for the intended audience. The entire purpose of teaching is to bridge the gap between where the listener currently is at, and where you want them to be.
Is the audience paying attention to the communicator? Countless factors can interfere with connection between the teacher and the listener. Some of them involve the way the information is communicated. Some of it relates to the environment. Sometimes, it involves the listener not caring about the content.