en-是个来自古法语的前缀，但其前身却是拉丁语的in-，原意是in或into。在现代英语构词中，en-是个动词性的派生前缀。它与名词或形容词相缀合，构成动词，其意思相当于to put into(使…置于…）或to make(使…）。em-是en-的异体，只出现在唇辅音字母 b, p与m之前。

先来认识几个由en-与名词构成的派生词。

enact [en-=to put into 使置于；act n. 法令=>“to put into an act 付诸于法令”→]v. make into a law制定（法律），颁布、通过 (法案）/ Congress enacted a bill to restrict the sale of guns. 国会通过一项限制枪支出售的法案。

enactment n. 制定，颁布；法令，条例

encircle [ en- = to put into 使置于；circle n. 圆圈=>“to put into a circle 使在圆圈中”→] v. form a circle around; surround 环绕； 包围/ Trees encircle the pond.树木环绕着水池。encirclement n. 环绕；包围

endanger [en-= to put into 使置于；danger n. 危险=>“to put into danger使处于危险中”→]v. cause danger to使遭到危险，危害，危及/The fire endangered the hotel's guests, but no lives were lost. 大火危及该旅馆的宾客，但无人丧生。

dangerment n. 危害

enforce[ en- = to put into 使置于；force n. 效力→]v. put into force; cause to be carried out 实施；执行/ Policemen and judges will enforce the laws.警察与法官要执法。

enforcement n. 实施，执行；厉行

enlist [ en- = to put into 使置于；list n. 名单=>“to put into the list 使列入征兵名单中 ”→]v. get to join the armed forces 征募，使服兵役 / Many men in the city were enlisted during the war.战争期间，该城许多男人被征人伍。

enlistment n. 征募；应募入伍；服役期