Learn Hardcore Japanese: asita kaisya de kaigi wo simasu. - I will have a meeting at the company tomorrow.

Time expressions like 明日 (tomorrow) function as adverbials in Japanese. They often appear without particles and simply indicate “when” the action takes place. Placing 明日 at the beginning makes it clear that you’re talking about something happening tomorrow.

Why do we use で after 会社 instead of に?

The particle で marks the location where an action occurs. Since you’re “holding a meeting” at the company, 会社で means “at the company.” In contrast, に would express a point of arrival or existence (“to the company” or “at the company” in the sense of being there), but not the place of an ongoing action.

Why is を used with 会議? Doesn’t を only mark direct objects of transitive verbs?

Exactly: を marks the direct object. In Japanese, many nouns can pair with する (“to do”) to become verbs. Here, 会議をする means “to do a meeting,” i.e. “to hold a meeting.” 会議 is what is being “done,” so it takes を.

Could I say 会議があります instead of 会議をします?

Yes—but the nuance differs:

会議があります literally “There is a meeting.” It focuses on the meeting’s existence or schedule.
会議をします literally “We’ll do/hold a meeting.” It emphasizes the action of holding it.

Why is there no explicit subject in the sentence?

Japanese often omits the subject when it’s clear from context. Here, it’s understood that “we,” “our company,” or “the staff” will hold the meeting. Adding a subject like 私たちは or 会社は is possible but usually unnecessary.

Can I change the word order in this sentence?

Yes. Thanks to particles, Japanese word order is flexible. Common alternatives include:
• 会社で　明日　会議をします。
• 明日　会議を　会社で　します。 (though less typical)
The verb normally stays at the end, but you can rearrange time, place, and object as long as each retains its correct particle.

What exactly does します mean in 会議をします?

します is the verb “to do.” When attached directly to certain nouns (会議, 宿題, 買い物, etc.), it creates a verb phrase meaning “to have/hold/do [that noun].” So 会議をします means “to hold a meeting.”

What effect does adding よ at the end have, as in 明日会社で会議をしますよ?

Adding よ makes the sentence more conversational and assertive. It signals that you’re informing or reminding the listener: “Just so you know, we’re having a meeting tomorrow at the office.”