Learn Hardcore Japanese: syukudai wo dasanakereba, sensei ni tyuuisaremasu. - If you don’t turn in your homework, you will be warned by the teacher.

Dictionary form: 出す
Negative: 出さない
Replace ない with なければ → 出さなければ (“if [you] don’t hand in”) Note: This pattern is general: 食べない → 食べなければ, 行かない → 行かなければ.

Can I think of 〜なければ as “unless”?

Often yes, because “if not X, Y” can translate as “unless X, Y.” But the core meaning is “if not.” Use “if not” as your default; “unless” is a natural translation in many contexts, including this sentence.

Can I use 〜ないと instead of 〜なければ? What’s the nuance?

Yes: 宿題を出さないと、先生に注意されます。

〜ないと is more casual and common in speech.
〜なければ is neutral to slightly formal.
Don’t confuse 〜ないと here with the “must” pattern 〜ないといけない; in this sentence it’s purely conditional (“if you don’t…”).

Why is 注意されます in the passive? What’s the active version?

Japanese often uses the passive to emphasize the person affected (and to imply it’s unwelcome).

Active: 先生が（私を）注意します。 “The teacher warns (me).”
Passive: （私は）先生に注意されます。 “I get warned by the teacher.” The passive is the natural choice for “be warned/scolded.”

What does 先生に do here? Could I use 先生から?

In passives, に marks the agent (by whom): 先生に = “by the teacher.”
You can also say 先生から注意されます; から frames the teacher as the source of the action. Both are common; に is the default for the agent of a passive.

Is 注意をされます also correct?

Yes. With many する verbs, を is optional:

注意する / 注意をする
注意される / 注意をされる Using を can feel a bit heavier/more formal, but both are correct.

What’s the nuance difference among 注意されます, 叱られます, and 怒られます?

注意されます: “be cautioned/admonished,” often corrective/instructive; not necessarily angry.
叱られます: “be scolded,” stronger, moral/disciplinary tone.
怒られます: “be gotten angry at,” emphasizes the teacher’s anger more than instruction.

Why use 出す instead of 提出する for “submit”?

Both can mean “submit.”

出す is everyday and natural in school talk: 宿題を出す.
提出する is more formal/administrative: 宿題を提出する. You could say: 宿題を提出しなければ、先生に注意されます。 (a bit more formal).

Who is the subject here—“I,” “you,” or “we”?

It’s omitted. In Japanese, the subject is often understood from context. Here it’s a general rule, so it reads as “you/one (students).” If you want to state it explicitly: （私は／あなたは）先生に注意されます。

Does されます mean future “will be,” or present “is”?

Non-past (〜ます) covers present/habitual and future. Here it states a general consequence (“you’ll get warned”), which English often renders with “will.”

Can I change the word order, like 先生に宿題を出さなければ注意されます?

You can reorder phrases fairly freely, but keep the conditional clause intact. Natural options:

宿題を出さなければ、先生に注意されます。 (original)
宿題を出さなければ先生に注意されます。 (no comma) Placing 先生に before the predicate is typical. Avoid splitting the conditional in awkward ways.

Is the comma after なければ necessary?

No. It just improves readability. Both …なければ、… and …なければ… are fine.

How can I make this more casual or more formal?

Casual: 宿題出さないと、先生に注意されるよ。 (drop を is common in speech)
More formal: 宿題を提出しなければ、先生から注意を受けます。 (use 提出 and 注意を受ける)

How do I say “You must hand in your homework” (a rule), not a consequence?

Use the obligation patterns:

宿題を出さなければなりません。
宿題を出さないといけません。 Both mean “must/have to submit homework.”

Can I add もし?

Yes, to emphasize the hypothetical:

もし宿題を出さなければ、先生に注意されます。 It doesn’t change the grammar, just adds “if” flavor.

Can I use 〜たら instead: 宿題を出さなかったら…?

You can: 宿題を出さなかったら、先生に注意されます。
However, for “if you don’t do X, Y (bad) happens,” 〜ないと or 〜なければ is more idiomatic. 〜たら can feel a bit more temporal/hypothetical.

Why is 宿題 marked with を and not は? Can I use は?

を marks it as the direct object of 出す.
You can topicalize: 宿題は出さなければ、先生に注意されます。 This makes “as for homework” the topic. Default, neutral statement uses を.

Does 〜なければ ever mean “I must” by itself?

In conversation, trailing off with 〜なければ／〜なきゃ can imply “I gotta …” by omitting いけない/ならない. Example: もう行かなきゃ… (“I’ve gotta go.”)
In this sentence, because a result clause follows, it’s the literal conditional “if not.”

How are the words read?

宿題（しゅくだい）
出す（だす）
注意（ちゅうい）
注意されます（ちゅういされます）
先生（せんせい）