In both spoken and written language, sentences and paragraphs are the basic units of meaning. In a written text, their boundaries are clear. In oral communication, however, these boundaries may blur.

In talks, then, use transitions to indicate the relationship between preceding sentences or paragraphs and those that follow. Or repeat a key phrase from the last sentence or paragraph to begin the next. While not every sentence or paragraph demands a transition, many do, especially those that elaborate upon a previous one or move toward a new point.

Connecting words (coordinators such as "but" or "and," subordinators such as "because" and "while," adverbs such as "however" and "nevertheless") also provide direction. Incorporate connectors that are appropriate to your meaning, to the meaning you want listeners to make. They can be particularly helpful in signaling that a change of topic—and thus a new paragraph—is to follow.

Listeners generally understand and retain only about a fourth of what they hear. A speaker can help them attain that fourth or perhaps even more by using a variety of well-constructed sentences of appropriate length. Sentence variety staves off the monotony that leads to inattention. Simple, compound, and complex sentences all have a place in oral communication, but no sentence should be so long or complicated that it defies a listener's ability to grasp its meaning.

Listeners often have difficulty locating the main point in sentences smothered by layers of modifiers, absolutes, or subordinate clauses. To ease that difficulty, sequence the parts of the sentence so that the most important information appears in a main clause and limit add-ons to what can be readily grasped aurally, as in this sentence: "In its preliminary phase, the study was slow to enlist participants, but as we refined recruitment methods, enrollment increased rapidly, reaching the required number in March 2016."

Help listeners navigate and comprehend your speech or presentation by varying the emphasis, volume, pitch, and cadence of your voice. These four elements can serve as oral punctuation marks and format signals.

• Stress especially significant words or phrases to emphasize their importance; increased stress on connecting words can alert audiences to the relationship among ideas.
• Volume changes can prepare listeners for new messages or additions to a previous one.
• Pitch, the degree of highness or lowness of your voice, can also be used for emphasis. While statements end at a level or slightly lower pitch than the rest of the sentence and questions end on a higher note, you can raise the pitch to express surprise or excitement, for example, and lower it to convey confidentiality or familiarity.
• Pace includes both the tempo (speed) and rhythm (pattern of sound and silence) with which you speak. Speak more slowly to provide emphasis. Speak faster to indicate enthusiasm or anticipation. Pause to increase audience attention, highlight a point, or transition from one point or paragraph to another.

Speeches and presentations are more than just the speaking aloud of a written document. They make different demands. Meet them—because no one can hear a parenthesis.