A subgroup is a smaller group inside a bigger group. The people or things in it still belong to the big group, but they share something extra that makes them stand apart — an age, a language, a job, a way of doing things.

A subgroup is a smaller groupSubgroup 是一個比較小的群體， inside a bigger group存在於一個比較大的群體裡面。The people or things in it still belong to the big group裡面的人或東西仍然屬於那個大群體， but they share something extra that makes them stand apart — an age, a language, a job, a way of doing things但他們有一個額外的共同點，讓他們顯得與眾不同——可能是年齡、語言、工作，或做事的方式。

If a study looks at 500 patients, the researchers might look separately at the subgroup of patients over sixty. If a company has a marketing team, there may be a subgroup that only handles social media.

If a study looks at 500 patients如果一項研究觀察500名病人， the researchers might look separately at the subgroup of patients over sixty研究者可能會另外單獨看六十歲以上病人這個 subgroup(次族群)。If a company has a marketing team如果一家公司有行銷團隊， there may be a subgroup that only handles social media裡面可能有一個只負責社群媒體的 subgroup(小組)。

It is a slightly formal, organising word: you meet it in reports, research papers, school planning, and committee talk more than in the street. It is also a technical term in mathematics, where a subgroup is a group sitting inside another group under the same operation — but a learner will meet the everyday sense far more often.

It is a slightly formal, organising word這是一個稍微正式、用來組織資訊的字， you meet it in reports, research papers, school planning, and committee talk more than in the street你在報告、研究論文、學校規劃和委員會討論裡遇到它，比在街頭巷尾更常見。It is also a technical term in mathematics, where a subgroup is a group sitting inside another group under the same operation它也是數學裡的專有名詞，指在同一種運算下，一個群嵌套在另一個群裡面—— but a learner will meet the everyday sense far more often不過學習者遇到日常這個意思的機會多得多。

Notice a small thing about size and importance: 'sub-' says the group is a part of something larger, and often it is smaller and less important, but not always. A subgroup can be the biggest and busiest part of an organisation and still be called a subgroup, because the name is about where it sits, not how much it matters.

Notice a small thing about size and importance注意一個關於大小和重要性的小地方： 'sub-' says the group is a part of something larger'sub-' 是說這個群體是更大東西的一部分， and often it is smaller and less important通常它比較小、也比較不重要， but not always但不總是這樣。A subgroup can be the biggest and busiest part of an organisation一個 subgroup 可以是一個組織裡最大、最忙碌的部分， and still be called a subgroup卻仍然被叫做 subgroup， because the name is about where it sits, not how much it matters因為這個名字講的是它所處的位置，不是它有多重要。

It can also be a verb — to subgroup something is to divide it into subgroups — but that use is rare and technical, and most people would just say 'divide' or 'split into groups'.

It can also be a verb — to subgroup something is to divide it into subgroups它也可以當動詞——to subgroup something 就是把它分成幾個 subgroups—— but that use is rare and technical不過這種用法很少見、也很專業， and most people would just say 'divide' or 'split into groups'大多數人會直接說 'divide' 或 'split into groups'。