This article series aims to eliminate usage errors and help non-native speakers to write clearly and fluently. We suggest that you always do proper research and use style guides effectively. For anything you are not sure of, feel free to ask us. Misused word deepen Alternatives improve, increase, bolster, boost, develop. Explanation “Deepen” is a difficult word to use correctly. In addition to its literal meaning (e.g., deepen a well), it can also be used figuratively to mean “to increase,” […]