“逐渐减少”常见的英文表达有：
gradually decrease： “gradually”意思是“逐渐地、逐步地” ，强调过程的渐进性；“decrease”是动词，意为“减少、降低” 。例如：The number of birds in this area has gradually decreased over the years.（这些年来，这个地区的鸟类数量逐渐减少了。）
gradually reduce：“reduce”同样表示“减少、降低”，与“gradually”搭配，也表达逐渐减少的意思。例如：We should gradually reduce our dependence on fossil fuels.（我们应该逐渐减少对化石燃料的依赖。）
decrease steadily：“steadily”意思是“稳定地、持续地” ，虽然和“gradually”略有区别，但也可表达一种持续且有序的减少过程。例如：The pollution level in the river has decreased steadily since the new regulations were implemented.（自新规定实施以来，河里的污染水平已稳步下降。）