Learn Hardcore Japanese: watasi ha asita no kaigi de yosan wo kakuninsimasu. - I will check the budget at the meeting tomorrow.

は marks the topic of the sentence. In 私は明日の会議で予算を確認します。, 私 is the topic, roughly “As for me…”. It doesn’t necessarily mean “I” is emphasized as the doer; it just sets the frame. If you wanted to emphasize that it is specifically “I (and not someone else)” who will do it, you could use 私が明日の会議で予算を確認します。 in a context like answering 誰が確認しますか。

Why is it 明日の会議 and not something like 明日に会議?

明日の会議 uses の to make a noun-noun phrase: “tomorrow’s meeting.” You’re identifying which meeting.

明日の会議で予算を確認します。 = “At the meeting that is tomorrow, I will check the budget.”
If you want to put “tomorrow” as the time of the action, you can say: 明日、会議で予算を確認します。 Here, 明日 is a time adverb and doesn’t need に.
明日に会議 is generally unnatural for “a meeting tomorrow.” You’d say 明日、会議があります or 会議は明日です.

Why is で used after 会議? Could I use に instead?

で marks the location/setting where an action takes place: 会議で = “at the meeting.”

Use で with actions done at the event: 会議で発表する／話す／確認する.
Use に for destination/participation: 会議に出る／参加する／行く.
Use に for time points: 3時に, 金曜日に. But with words like 明日／今日／来週, に is often omitted when they’re just time adverbs.

Can I drop 私は?

Yes. Japanese often omits subjects when clear from context. 明日の会議で予算を確認します。 is natural. Keep 私は if you need to set contrast or clarity (e.g., when multiple people are being discussed).

Does this sentence express future tense?

Japanese has a non-past form that covers present and future. Here, 明日 supplies the future meaning. If you want to emphasize intention/schedule, you can say:

明日の会議で予算を確認するつもりです。 (intention)
明日の会議で予算を確認する予定です。 (scheduled plan)

How do I read the words?

私: わたし
明日: あした (neutral) or あす (more formal/business); みょうにち (very formal/written)
会議: かいぎ
予算: よさん
確認します: かくにんします

What’s the nuance difference between 確認する, 確かめる, and チェックする?

確認する: formal/neutral “to confirm/verify,” common in business.
確かめる: more colloquial “to make sure/verify” (native verb).
チェックする: casual “to check,” often for quick or routine checks. In formal writing/speech, 確認する is safer. You can also say 再確認する for “double-check.”

Is 確認します polite enough for business?

Yes, it’s standard polite. For more formality/humility:

確認いたします。 (humble)
確認させていただきます。 (requesting permission nuance) When asking the other party to check, use:
ご確認ください。 Avoid ご確認します (unnatural). Use the noun form with set phrases like ご確認
- ください／をお願いいたします.

Can I say 予算について確認します?

It’s possible, meaning “confirm regarding the budget,” but 予算を確認します is more direct and typical when the budget itself is the object. Use 〜について when the object isn’t the thing being directly verified but the topic area:

Asking someone: 予算についてご確認ください。 (Please check regarding the budget.)

How flexible is the word order?

Japanese allows reordering of chunks as long as the verb stays at the end and particles stick to their words. All are natural with slight nuance shifts:

明日の会議で私は予算を確認します。 (keeps focus on location first)
予算は明日の会議で確認します。 (topicalizes the budget)
私は明日の会議で予算を確認します。 (original) Avoid moving します away from the end or separating nouns from their particles.

What does を mark here?

を marks the direct object of the verb. 予算を確認します = “confirm the budget.” You need を with transitive verbs like 確認する. With intransitives (like 分かる), you wouldn’t use を: 予算が分かります.

How would I say “during the meeting” instead of “at the meeting”?

Use 会議中に to emphasize “during” the meeting’s duration:

明日の会議中に予算を確認します。 (at some point during the meeting) 会議で is more neutral “at/in the setting of the meeting.”

How do I politely ask someone, “Will you check the budget at tomorrow’s meeting?”

Several options by politeness:

Polite: 明日の会議で予算を確認しますか。
More courteous request: 明日の会議で予算をご確認いただけますか。
Even softer: 明日の会議で予算をご確認いただけると助かります。

Can I use あす or みょうにち instead of あした?

Yes:

あす: more formal/businesslike than あした. 明日の会議 can be read あすのかいぎ.
みょうにち: very formal/written or announcements. In ordinary speech, あした/あす is better.

Is there a noun-phrase version like “do a confirmation of the budget”?

Yes: 明日の会議で予算の確認をします。 This nominalizes 確認. It sounds slightly more formal/technical. Both 予算を確認します and 予算の確認をします are common in business.