Learn Hardcore Korean: gyosil gongjisahangi imeillo wasseoyo.

공지 comes from 公示 in Chinese characters, meaning “public announcement.”
사항 means “matter,” “item,” or “thing.”
Together, 공지사항 refers to an official notification or announcement shared within a group.

What does 교실 공지사항 mean, and how do the words relate?

교실 공지사항 means “classroom notice.” Here, 교실 (“classroom”) modifies 공지사항 to specify the context. It’s not two separate actions or subjects; instead it’s one phrase where 교실 tells you whose notice it is.

Why is 이메일로 used, and what role does the particle -로 play?

이메일로 breaks down into 이메일 (“email”) + -로, which indicates the means or method. So it translates to “by email” or “via email.” Whenever you want to express “by [method],” you can often use -로 after the noun.

Could I use 메일로 instead of 이메일로?

Yes. 메일로 is simply a shortened, more casual form of “email.” Both 이메일로 and 메일로 mean “by email,” though 이메일로 sounds slightly more formal or complete.

Why is 공지사항 followed by 이 (the subject marker) instead of 은/는 (the topic marker)?

-이/가 marks the grammatical subject, introducing new information (what came). Here, 공지사항이 is the thing that “came.” If you used -은/는, like 공지사항은, you’d be setting it as the topic and possibly contrasting it with something else (e.g., “As for the notice, it came by email, not by text”).

What does 왔어요 literally mean, and why not use 받았어요 (“received”)?

왔어요 is the past polite form of 오다 (“to come”). Literally, “it came.” In this sentence, you’re saying “the notice came via email,” emphasizing the arrival of the notice.
If you say 받았어요, you’re focusing on the action of you receiving it: 공지사항을 이메일로 받았어요 = “I received the notice by email.” Both are correct but highlight different perspectives (the arrival vs. your action).

Why isn’t there an explicit subject like 저 (“I”) in this sentence?

Korean often omits subjects when they’re understood from context. Here, it’s clear that you experienced the notice arriving, so adding 저 (I) is unnecessary. The sentence centers on the 공지사항 itself.

What is the default word order here, and can I rearrange it?

Standard order in this sentence is:
[Modifier + Subject] + [Method] + [Verb] → 교실 공지사항이 (subject) 이메일로 (method) 왔어요 (verb).
Korean word order is flexible for emphasis, so 이메일로 교실 공지사항이 왔어요 is also possible (emphasizing “by email”). However, putting the verb elsewhere (e.g., 교실 공지사항이 왔어요 이메일로) sounds unnatural.

What tense and politeness level is used with 왔어요, and how can I change it?

왔어요 is past tense in the polite -요 form (often called the “해요” style).

More formal: 왔습니다.
More casual/friendly: 왔어.
Choose the level depending on your relationship with the listener and the situation.