kinou watasi ha kanozyo ni atarasii ryokoukeikaku wo misemasita

は marks the topic of the sentence.

So 私は means something like:

• as for me
• speaking of me

In this sentence, 私 is also the person doing the action, so in natural English it becomes I.

A very literal breakdown would be:

• 昨日 = yesterday
• 私は = as for me
• 彼女に = to her
• 新しい旅行計画を = a new travel plan
• 見せました = showed

So the whole sentence is essentially As for me, yesterday, to her, a new travel plan, showed.

That sounds strange in English, but it is normal Japanese structure.

Many time words in Japanese can be used without a particle.

So 昨日 can simply mean yesterday by itself, functioning like an adverb.

That is very common. For example:

• 昨日行きました = I went yesterday
• 今日勉強します = I will study today
• 明日会います = I will meet someone tomorrow

You can sometimes see time expressions with particles in other contexts, but with words like 昨日, 今日, and 明日, no particle is usually needed.

In this sentence, に marks the person who receives the action.

With 見せる meaning to show, the pattern is often:

• someone に something を 見せる
• show something to someone

So:

• 彼女に = to her
• 新しい旅行計画を = the new travel plan
• 見せました = showed

This is why 彼女に is the person receiving what was shown.

を marks the direct object of the verb.

The direct object is the thing directly affected by the action.

Here, the thing being shown is:

• 新しい旅行計画 = new travel plan

So:

• 新しい旅行計画を見せました = showed a new travel plan

A simple way to remember it:

• に = to the person
• を = the thing being acted on

新しい is an い-adjective, and in Japanese, an い-adjective goes directly before the noun it modifies.

So:

• 新しい本 = a new book
• 新しい車 = a new car
• 新しい旅行計画 = a new travel plan

You do not need a word like of or a or any linking particle here.

So 新しい旅行計画 is just one noun phrase: new travel plan.

The dictionary form is 見せる, which means to show.

見せました is the polite past form.

Formation:

• dictionary form: 見せる
• polite non-past: 見せます
• polite past: 見せました

So 見せました means showed or have shown, depending on context, though in this sentence it is naturally showed.

Also, be careful not to confuse:

• 見る = to see / to look
• 見せる = to show

They are related, but they are different verbs.

Not completely. Japanese word order is more flexible than English word order, because particles show each word’s role.

The most important thing is usually that the verb comes at or near the end.

So this sentence could also appear as:

• 私は昨日彼女に新しい旅行計画を見せました。
• 彼女に私は昨日新しい旅行計画を見せました。

These variations may sound slightly different in emphasis, but the basic meaning stays the same because:

• は shows the topic
• に shows the recipient
• を shows the direct object

That said, some orders are more natural than others, and the original sentence is perfectly normal.

Yes. Very often, Japanese omits subjects or topics when they are clear from context.

So in a real conversation, someone might simply say:

• 昨日、彼女に新しい旅行計画を見せました。

That would still naturally mean I showed her a new travel plan yesterday, if it is already understood that the speaker is talking about themselves.

Japanese often leaves out words that English normally requires.

It can, depending on context, but in this sentence it is most naturally understood as her.

Why?

Because 彼女に is being used as the person receiving the action:

• I showed a new travel plan to her

Out of context, 彼女 can mean:

• she
• her
• girlfriend

Context decides which meaning is intended.

So yes, it could refer to someone’s girlfriend, but grammatically in this sentence it is functioning as to her.

Because 見る means to see or to look at, while 見せる means to show.

Compare:

• 私は旅行計画を見ました。 = I looked at / saw the travel plan.
• 私は彼女に旅行計画を見せました。 = I showed the travel plan to her.

So if the meaning is showed, then 見せる is the correct verb.

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

So this sentence would normally be written like this:

• 昨日私は彼女に新しい旅行計画を見せました。

Or with punctuation:

• 昨日、私は彼女に新しい旅行計画を見せました。

The spaced version is just a learner-friendly way to make the parts easier to see.

A helpful pattern is:

• time + topic + recipient に + object を + verb

For this sentence:

• 昨日 = time
• 私は = topic / speaker
• 彼女に = recipient
• 新しい旅行計画を = object
• 見せました = verb

So the pattern is basically:

• Yesterday, I showed her a new travel plan.

This is a very useful pattern to learn, because you can reuse it with many other verbs:

• 私は彼に写真を送りました。 = I sent him a photo.
• 私は先生に宿題を出しました。 = I submitted homework to the teacher.
• 私は友達に日本語を教えました。 = I taught Japanese to my friend.