kinou, sensei ni atarasii zisyo wo itadakimasita.

Because に marks the source of receiving here.

In this sentence, the speaker is receiving something, so:

• 先生に = from the teacher
• 新しい辞書を = a new dictionary (the thing received)

With verbs like もらう and いただく, the giver is often marked by に.

So:

• 先生にいただきました = received from the teacher

You can think of に here as showing who it came from.

Because を marks the direct object of the verb: the thing that was received.

In this sentence:

• 先生に = from the teacher
• 新しい辞書を = the new dictionary
• いただきました = received

So を answers the question What did you receive?
Answer: 新しい辞書.

いただきました is the humble and polite version of もらいました.

Both can mean received, but the nuance is different:

• もらいました = neutral/polite
• いただきました = humble, respectful

When the speaker receives something from a teacher, boss, customer, or someone deserving respect, いただく is often more appropriate because it lowers the speaker and shows respect toward the giver.

So this sentence sounds more natural if the speaker wants to be polite about receiving something from a teacher.

It is the polite past form of いただく.

Breakdown:

• dictionary form: いただく
• polite present: いただきます
• polite past: いただきました

So いただきました means received in a polite, humble way.

This verb can also mean eat/drink in humble speech, depending on context, but here it clearly means receive.

Because Japanese is basically an SOV language: subject-object-verb.

English often uses:

• I received a new dictionary from my teacher yesterday.

Japanese usually places the verb last:

• 昨日、先生に新しい辞書をいただきました。

A rough structure is:

• 昨日 = yesterday
• 先生に = from the teacher
• 新しい辞書を = a new dictionary
• いただきました = received

The main verb typically comes at the end of the clause.

Because Japanese often omits information that is clear from context.

In English, you usually need to say I, but in Japanese, if it is obvious that the speaker is talking about themselves, 私は is often left out.

So this sentence naturally implies:

• (I) received a new dictionary from my teacher yesterday.

If you add 私は, it is still grammatical:

• 私は昨日、先生に新しい辞書をいただきました。

But it may sound less natural unless you want contrast or emphasis.

新しい is an i-adjective, and it directly modifies the noun 辞書.

So:

• 新しい辞書 = new dictionary

This works similarly to English adjective + noun order:

• new dictionary
• 新しい辞書

No extra word like a or the is needed.

Yes, 昨日 can go in other places too. Japanese word order is more flexible than English, as long as the particles still show the relationships.

For example, these are all possible:

• 昨日、先生に新しい辞書をいただきました。
• 先生に昨日、新しい辞書をいただきました。
• 先生に新しい辞書を昨日いただきました。

Putting 昨日 first is very common because time expressions often appear near the beginning of the sentence.

It sets the scene first: As for yesterday...

It can mean any of those depending on context.

Japanese often leaves out information that English requires, such as:

• my
• the
• a

So 先生 here could be understood as:

• my teacher
• the teacher
• a teacher

In most real situations, context tells you which one is meant. If the meaning shown to the learner is my teacher, that is a very natural interpretation.

Yes, 先生から新しい辞書をいただきました is also possible.

Both に and から can mark the giver with receiving verbs, but there is a nuance:

• に is very common and neutral with もらう / いただく
• から emphasizes the starting point or source a bit more: from

So:

• 先生にいただきました = received from the teacher
• 先生からいただきました = received from the teacher

Both are grammatical. In many cases, に is the more standard choice with いただく.

They describe the same event from different viewpoints.

1. 昨日、先生に新しい辞書をいただきました。

   • focus: I received
   • verb: いただく (humble)

2. 昨日、先生が新しい辞書をくれました。

   • focus: the teacher gave (to me/us)
   • verb: くれる

So:

• いただく / もらう = receiver-centered
• くれる = giver-centered

Because the giver is 先生, using いただきました is especially polite and respectful.

The comma is optional, but it helps readability.

Since 昨日 is a time expression at the start of the sentence, the comma creates a small pause:

• Yesterday, ...

Japanese punctuation is often more flexible than English punctuation, and writers use commas to make the sentence easier to read.

So:

• 昨日先生に新しい辞書をいただきました。 is possible
• 昨日、先生に新しい辞書をいただきました。 is easier to read

No. Normal Japanese writing usually does not use spaces between words.

This sentence would normally be written as:

昨日、先生に新しい辞書をいただきました。

Spaces are often added in textbooks or beginner materials to make the sentence structure easier to see.

So the spaced version is just a learning aid, not standard writing.

It depends on the situation.

Because いただきました is polite and humble, it is very natural if:

• you are speaking politely
• you are talking about receiving something from a teacher
• you want to sound respectful

In casual conversation with friends, you might instead say:

• 昨日、先生に新しい辞書をもらった。

That is less formal and less humble.

So the original sentence is not strange at all; it just has a polite, respectful tone.