When to use 下一个 and when just 下一 to translate English next? “下” means "next" in English but the latter "一" or "个" is not a fixed phrase with "下" “一” is a numeric word plus "个” (a unit word) So from linguistics speaking, the structure of the phrase is: 方位词（localizer）+数词(numeric word)+量词(Unit word) 或者名词(noun) So you can substitute any of them, such as:
grammar - when is the suffix 边 面 required? - Chinese Language Stack . . . there happen to be certain differences between usages of different nouns of locality which simply have to be learned, e g NP +上、下、前、后、里、内、外、中、间 exist，while 东、西、南、北、左、右 cannot be used the same way, also depending on whether referring to space or time or sequence order 前、后 are used
translation - How do you translate 下沉市场 to English? - Chinese . . . 市场 here refers to 消费市场 (consumer Market) 下沉市场 (downward reaching consumer Market) refers to the expanding market (from the city area with high population density and high-income population) to the rural areas (with low population density and low-income population but much larger area)