Final answer:
Signal words in introductions indicate that the words or ideas that follow come from another source. Examples of signal words include 'acknowledges', 'denies', and 'points out'.
Step-by-step explanation:
Signal words in introductions serve to indicate that the words or ideas that follow come from another source. Signal phrases often contain a verb that indicates the tone or intention of the author. These phrases vary in placement and wording to avoid monotony. Examples of signal words and phrases for introductions include 'acknowledges', 'denies', and 'points out'.