Gallery Determination A quality that makes you continue trying to do or achieve something that is difficult. Stamina Great physical or mental strength that allows you to continue doing something for a long time. Strength The ability to resist being moved or broken by a force. Grit Mental toughness and courage. Endurance The ability to do something difficult for a long time. Willpower The ability to control yourself : strong determination that allows you to do something difficult . Fortitude Strength of mind that enables a person to encounter danger or bear pain or adversity with courage. Vigor Active bodily or mental strength or force; intensity of action or effect. Enthusiasm Strong excitement about something : a strong feeling of active interest in something that you like or enjoy.