ashita sensei ni shomei o moraimasu.

I will get a signature from the teacher tomorrow.

Breakdown of ashita sensei ni shomei o moraimasu.

• を: direct object particle
• 先せん生せい: teacher
• に: indirect object particle
• 明日あした: tomorrow

Questions & Answers about ashita sensei ni shomei o moraimasu.

Who is the subject here? Is it the teacher or me?

The implied subject is the receiver: “I” (or “we”). With もらう, the sentence is from the receiver’s point of view. So the sentence means “I will receive a signature from the teacher tomorrow.” If you want to make the subject explicit, you can say: 私は明日先生に署名をもらいます。

Why is 先生 marked with に? Could I use から instead?

With もらう, the giver/source is marked by に or から.

• に is common when the giver is a person you interact with directly: 先生に署名をもらう.
• から emphasizes “from” as a source and works with people and institutions/things: 先生から/大学から/会社からもらう. Both 先生に and 先生から are fine here, with only a slight nuance difference (に feels a touch more direct/personal).

Why does 署名 take を?

もらう treats the received item as a direct object. The pattern is “Person に Thing を もらう.” Here, 署名 is the “thing,” so it takes を: 署名をもらいます.

Why is there no particle after 明日? Is 明日に wrong?

Time words like 明日, 今日, 来週 often function as adverbs without a particle. 明日に is generally not used to mean “tomorrow” in this kind of sentence. You do use に with specific clock times/dates (3時に, 1月1日に). 明日に can appear in special contexts (e.g., scheduling decisions: 明日にします), but not here.

Is the word order fixed? Can I move 明日 or 先生に around?