These six verbs overlap, but they draw attention in slightly different ways. Choose according to whether you mean importance, a written mark, or a more noticeable feature.
- Emphasize is a general choice for giving something special importance or attention. The teacher emphasized the need to check our answers. It works in everyday conversation and formal writing.
- Stress often means saying firmly that something matters. The guide stressed that everyone must stay together. In this sense, it is close to emphasize; it does not mean causing worry.
- Highlight draws attention to selected information or important features. The report highlights three areas for improvement. It also means marking text with a bright color: I highlighted the dates in yellow.
- Underline can mean drawing a line beneath text: Please underline the correct answer. Figuratively, it makes importance clear: The delay underlines the need for better planning.
- Underscore means emphasizing something, often in formal writing. The findings underscore the importance of regular exercise. It is especially common when evidence or events show why something matters.
- Accentuate makes a feature or difference more noticeable. The dark frame accentuates the bright colors. Unlike the others, it often concerns appearance rather than an important message.
These are tendencies, not strict boundaries. You can often replace emphasize with stress without changing the basic meaning. For instructions about marking text, however, specify whether you want color or a line beneath the words.