Learn Hardcore Japanese: watasi ha asita made ni syorui wo teisyutusimasu.

明日まで = until tomorrow. A state/action continues up to (and includes) tomorrow as the limit.
- 店は明日まで休みです。= The store is closed until tomorrow.
明日までに = by tomorrow. A one-off action is completed at or before the deadline.
- 明日までに書類を提出します。= I’ll submit the documents by tomorrow.

Use まで for ongoing states; use までに for deadlines/completion of an action.

Can I say 明日まで提出します?

You can, but it means “I will keep submitting until tomorrow” (a repeated/continuous action), which sounds odd for a single submission. For a deadline, say 明日までに提出します.

Is 私 necessary here?

No. Japanese often drops first-person pronouns when context is clear. 私 in 私は adds topical/contrastive emphasis (“as for me”). Natural versions:

私は明日までに書類を提出します。(more explicit/contrastive)
明日までに書類を提出します。(natural, default in context)

What does は do here? What if I used が instead?

は marks the topic: “As for me, …” It presents background and can imply contrast.
が marks the grammatical subject and often adds focus: “It is I who will submit…” Examples:
私は明日までに書類を提出します。= As for me, I’ll submit by tomorrow.
私が明日までに書類を提出します。= I (not someone else) will submit by tomorrow.

Why is に used after まで? Is までに a set expression?

Yes. まで marks the endpoint (“until”), and adding に targets that endpoint as a deadline point: まで + に → までに (“by”). With deadlines and punctual actions, you need までに. Think “no later than [time].”

Where can I put the time phrase in the sentence?

Japanese word order is flexible. Common options:

明日までに書類を提出します。
書類を明日までに提出します。
明日までには書類を提出します。(adds は to topicalize the deadline; nuance: “at least by tomorrow” / emphasis on the deadline)

Why is を used with 書類? How do I add the recipient?

を marks the direct object of a transitive verb. 提出する takes what you submit as its object: 書類を提出する.
Recipient is marked with に. You can have both:
- 先生に明日までに書類を提出します。
- 明日までに先生に書類を提出します。 Both are fine; having two に is natural here (recipient に and deadline までに).

What’s the nuance difference between 提出する and 出す? And is 提出します polite?

提出する: formal “submit/turn in,” typically for documents, reports, assignments.
出す: broader “put out/hand in,” more casual; can be used with documents but less formal. Politeness:
提出します: standard polite.
提出いたします: humble (business/formal, toward superiors/clients).
書類を出します: casual/neutral; fine in informal settings.

Does 提出します mean future tense?

Japanese non-past covers present and future. Context supplies “future.” For explicit nuance:

明日までに提出します。= I’ll submit by tomorrow.
明日までに提出するつもりです。= I intend to submit by tomorrow.
明日までに提出する予定です。= I’m scheduled/planning to submit by tomorrow.

How do you read 明日 and does the reading change the tone?

あした: most common, everyday.
あす: slightly more formal/official (announcements, written notices).
みょうにち: very formal.
All mean “tomorrow”; choose based on register.

Does までに include the deadline itself?

Yes. までに means “by, no later than” the specified time. The action may occur before or exactly at that time, but not after.

三時までに来てください。= Come by 3:00 (at or before 3:00).

Can I omit particles like を or は in casual speech?

Dropping 私 and sometimes は is common in conversation.
を can be dropped in very casual speech, but it’s safer to keep it, especially in writing or as a learner.
Do not drop the に in までに; removing it changes meaning (まで ≠ deadline).

How do I specify an exact time, or say “sometime during tomorrow”?

Exact time: 明日の17時までに書類を提出します。= I’ll submit by 5 p.m. tomorrow.
“Within tomorrow”: 明日中に書類を提出します。= I’ll submit sometime during tomorrow. Note: 明日までに allows “any time from now up to the end of tomorrow,” while 明日中に restricts it to “sometime on tomorrow (not today).”

How do I say “I haven’t submitted it yet”?

まだ書類を提出していません。= I haven’t submitted the documents yet.
Avoid: まだ提出しません (that means “I won’t submit yet,” a deliberate decision).
If ability is the issue: まだ提出できていません。= I haven’t been able to submit yet.

How can I politely say “Please submit the documents by tomorrow”?

明日までに書類を提出してください。= Please submit the documents by tomorrow.
明日までに書類の提出をお願いします。= I’d like to request submission of the documents by tomorrow. (softer/business-like)

How can I turn the deadline phrase into a modifier for a noun?

Use までの:

明日までの書類 = documents that are due by tomorrow.
提出期限は明日までです。= The submission deadline is until tomorrow. (using まで for the deadline limit itself)

How do I indicate the number of documents?

Japanese nouns don’t mark plural by default. Add a counter:

書類を一部提出します。= I’ll submit one copy.
書類を三部提出します。= I’ll submit three copies. (部 is common for copies of documents)