The document discusses transition signals in writing academic English. It defines transition signals as connecting words or phrases that link sentences and paragraphs together smoothly to guide the reader through ideas. Without transition signals, writing can have abrupt jumps or breaks. The document provides examples of transition signals that lead the reader forward, imply building ideas, make comparisons, or draw conclusions. It then gives a list of common transition signals categorized by the relationship they indicate, such as sequence, time, comparison, or conclusion.