Learn Hardcore Japanese: asita sensei ga watasitati ni atarasii kanzi wo osiemasu. - Tomorrow the teacher will teach us new kanji.

In Japanese, time words like 明日 (tomorrow) often act as adverbials and can stand alone at the sentence’s start without a particle. It tells us when the action happens, so you don’t need に or を there.

Why is 先生 marked with が instead of は?

が marks the grammatical subject—the one doing the action—in a neutral, new-information statement. If you used は (topic marker), it would mean “As for the teacher, …” and might imply contrast or that you’ve already been talking about the teacher.

Why do we have both が and に in this sentence?

が indicates the subject (先生 = “the teacher”), while に indicates the indirect object or the recipient of the action (私たちに = “to us”). The verb 教えます is ditransitive (“teach someone something”), so it needs both a subject and an indirect object.

Why is the verb 教えます in the non-past form even though the time is tomorrow?

Japanese doesn’t have separate present and future tenses. The non-past form 教えます can mean “(will) teach” or “teach” in general. The word 明日 makes it clear you’re talking about the future.

Can we change the word order? For example, 先生が新しい漢字を明日私たちに教えます?

Yes. Japanese word order is quite flexible because the particles (が／を／に) mark each phrase’s role. However, putting the time word (明日) at the very front is most natural. Other orders are grammatically fine but may sound less smooth.

Could we omit 先生が? And if so, when would that be okay?

Absolutely. Japanese often drops the subject when it’s clear from context. If you’re already talking about the teacher, you can say 明日私たちに新しい漢字を教えます and everyone will understand who’s doing the teaching.

Could we use へ instead of に in 私たちに?

No—へ generally indicates direction or movement toward a place or goal (“to/toward”). For verbs like 教える that take an indirect object (the person receiving something), you use に (“teach to someone”).

Why do we say 新しい漢字 and not 漢字新しい?

In Japanese, adjectives (like 新しい) always come before the noun they modify (漢字). You can’t put the adjective after the noun in a simple attributive phrase.

Why do we use を after 漢字?

教える is a transitive verb that directly acts on something (the “thing” being taught). That “thing” (新しい漢字) is the direct object, so it takes the object marker を.

What changes if we use 先生は instead of 先生が?

Using 先生は makes “the teacher” the topic rather than simply the subject. It shifts the nuance to “As for the teacher, (he) will teach us new kanji tomorrow,” perhaps contrasting him with someone else or implying you’ve already been discussing him. The main action focus subtly shifts.