Substantial: adj. large in amount or value; important大量的；價值巨大的；重大的（同義詞considerable; significant）：e.g., a substantial amount of money 壹大筆錢；a substantial change/improvement 重大變化/改進；
Substantially: adv. 1. very much; a lot非常；大大地（同義詞considerably; significantly）：e.g., The costs have increased substantially. 成本大大提高了。2. (formal) mainly; in most details; even if not completely 基本上；大體上；總是來說：What she says is substantially true. 她的話大體符合事實。
Substantive: adj. 1. (formal) dealing with real, important or serious matter實質性的；本質上的；重大的；嚴肅認真的：substantive issues/matters實質性問題 2. Substantive as an adjective also has a special meaning in law, wherein it is distinguished from “procedural” (e.g., whether one committed murder is a “substantive” issue, while whether one side or the other has the burden of proof is a “procedural" one). Substantive law實體法；procedural law程序法。
A substantial change is a big change; a substantive change is a change in the substance of something. Substantial表示量；substantive表示質。
在合同中常見的Substantially例句：
Management Agreement means the agreement between the Fund and the Manager, in substantially the form attached as Exhibit I to the Agreement. 管理合同是指基金與管理人之間簽署的、與本合同附件I中所載格式基本相同的合同。
每壹集團公司按其正常業務過程及按其過往大致相同的形式進行其業務。Each Group Company has conducted their respective businesses in ordinary course, in substantially the same manner in which they had been previously conducted.
（由得法翻譯總結和整理）