energy : 用于人时，指工作时焕发出的精力或干劲。
- Since I started eating more healthily I've got so much more energy.
- I was going to go out this evening, but I just haven't got the energy.
- I didn't even have the energy to get out of bed.
- Her writing is full of passion and energy (= enthusiasm).
force : 着重指克服障碍，推动人或物朝所要求的方向运动或能产生明显效应的力量。
- The force of the wind had brought down a great many trees in the area.
- She slapped his face with unexpected force.
- Teachers aren't allowed to use force in the classroom.
- The police were able to control the crowd by sheer force of numbers (= because there were more police than there were people in the crowd).
power : 最普通用词，泛指一切力量或能力等。
- Our car doesn't have enough power to tow a trailer.
- Weightlifters have tremendous power in their arms and legs.
- Scientists are working to harness the power of the atom.
- The economic power of many Asian countries has grown dramatically in recent years.
might : 多指巨大或超人的力量。
- Pizarro defeated the might of the Inca Empire with only a few hundred men.
- She struggled with all her might to get free.
strength : 指机体内部的能力，是依靠身体组织而存在的力，经使用就变为force。
- She had the strength and stamina to take the lead and win the gold medal.
- Admitting you've made a mistake is a sign of strength, not weakness.
- He showed great strength of character when he refused to accept the bribes.
- We will struggle on, drawing our strength from the courage of others.
- Much of the country's military strength lies in its missile force.
vigour : 指由生命元气的存在所产生的活力、精力。
- They set about their work with youthful vigour and enthusiasm.