tomodati ha yakusoku ni okureta watasi wo yurusite, mata ganbarou to hagemasite kureta.

In Japanese, a clause can come directly before a noun and modify it.

So:

• 約束に遅れた私 = I, who was late for the appointment
• more literally: the me who was late for the appointment

Here, 約束に遅れた is a relative clause modifying 私.

This is a very common Japanese pattern:

• 本を読んでいる人 = the person who is reading a book
• 昨日会った友達 = the friend I met yesterday

So 約束に遅れた私を許して means forgave me, who was late for the appointment.

遅れる often takes に when it means to be late for something.

So:

• 学校に遅れる = be late for school
• 電車に遅れる = miss / be late for the train
• 約束に遅れる = be late for an appointment / be late in keeping a promise

In this sentence, 約束 most naturally means an appointment or arrangement rather than a general abstract promise.

The particle に marks the thing/event that you were late for.

は marks 友達 as the topic of the sentence.

So the sentence is framed as:

• As for my friend, ...

This is very natural when talking about what that friend did next.

If you used が, it would sound more like you were specifically identifying the friend as the one who did this, often with a bit more focus or contrast.

Very roughly:

• 友達は = speaking about my friend
• 友達が = it was my friend who...

In this sentence, は is the more neutral narrative choice.

The を marks 私 as the direct object of 許して.

So:

• 約束に遅れた私を許して = forgave me for being late for the appointment

It does not mean that 私 is the subject of 遅れた because inside the relative clause, Japanese often leaves that relationship to be understood from meaning.

In 約束に遅れた私, the noun 私 is the one who did the being late.

Then in the larger sentence, 私 becomes the object of 許して because of を.

The て-form is being used to connect actions.

So:

• 許して、また頑張ろうと励ましてくれた = forgave me, and encouraged me to try again

This kind of て-form linking is extremely common in Japanese. It often corresponds to and, then, or sometimes after doing in English.

Here the friend did two related actions:

1. forgave me
2. encouraged me

So 許して links naturally to the next verb phrase.

Not a special grammatical meaning beyond helping readability and rhythm.

The sentence would still be grammatical without it:

• 友達は約束に遅れた私を許してまた頑張ろうと励ましてくれた。

The comma just helps separate the two linked actions:

• forgave me
• encouraged me

Japanese punctuation is often more flexible than English punctuation.

頑張ろう is the volitional form of 頑張る.

It usually means something like:

• let’s do our best
• let’s keep trying
• let’s give it another try

With また, it becomes:

• let’s try again
• let’s do our best again

In this sentence, it is the content of the encouragement. The friend encouraged the speaker with the idea of trying again / keeping at it.

This is about nuance.

• 頑張れ = Do your best!
  Strong, direct, can sound forceful.
• 頑張って = Do your best / Hang in there
  Common and natural encouragement.
• 頑張ろう = Let’s do our best / Let’s keep trying
  Inclusive and softer.

In this sentence, 頑張ろう suggests the friend is encouraging in a warm, supportive way, almost as if saying Come on, let’s keep going rather than commanding the speaker.

That fits well with 励ましてくれた.

Here と marks the content of what was said, thought, or expressed.

So:

• また頑張ろうと励ます = to encourage someone by saying/thinking “let’s try again”

This is similar to quotation/complement と used with verbs like:

• 言う = say
• 思う = think
• 決める = decide
• 願う = wish

Even though there are no actual quotation marks, the idea is that the encouragement contained the message また頑張ろう.

Because 励ます can take the content of the encouragement.

So the pattern is:

• X と 励ます = encourage someone by saying / with the message X

In other words, the friend encouraged the speaker with the idea:

• また頑張ろう

It is similar to English expressions like:

• He encouraged me, saying, “Let’s try again.”

Japanese often uses と this way without needing explicit quote marks.

励ましてくれた is:

• 励まして = encouraged
• くれた = did that for me

The verb くれる adds a sense that someone did something as a favor or in a way beneficial to the speaker.

So:

• 励ました = encouraged
• 励ましてくれた = kindly encouraged me / encouraged me for my benefit

This makes the sentence feel more personal and appreciative from the speaker’s point of view.

Grammatically, it is a main verb plus an auxiliary construction:

• 励ます → 励まして
• くれる → くれた

Together, they function as one predicate meaning:

• encouraged me for my benefit
• was kind enough to encourage me

This kind of combination is extremely common:

• 教えてくれた = taught me / told me for my benefit
• 手伝ってくれた = helped me
• 待ってくれた = waited for me

Explicitly, 私を is the object of 許して.

For 励ましてくれた, the object is omitted, but it is understood to be the same person: me.

So the structure is basically:

• 友達は [約束に遅れた私を] 許して、[私を] また頑張ろうと励ましてくれた。

Japanese often omits repeated objects when they are obvious from context.

Because Japanese often leaves out words that are already clear.

If you repeated it, it would still be understandable:

• 友達は約束に遅れた私を許して、私をまた頑張ろうと励ましてくれた。

But that sounds heavier and less natural than simply omitting it.

Japanese prefers omission when the meaning is obvious.

The subject is understood to be 私.

So:

• 約束に遅れた私 = I, who was late for the appointment

Japanese relative clauses usually do not require an explicit subject marker inside the clause if the meaning is clear.

You do not need something like:

• 私が約束に遅れた私

That would be unnatural here.

It could theoretically mean promise, because 約束 can mean both promise and appointment/arrangement.

But with 約束に遅れる, the most natural reading is usually:

• to be late for an appointment / arranged meeting

If the intended meaning were more like I was late in keeping a promise, context would usually make that clearer.

So in this sentence, learners should probably understand 約束 as an appointment or arrangement.

A useful way to break it up is:

• 友達は
• 約束に遅れた私を許して
• また頑張ろうと励ましてくれた

That gives:

1. As for my friend,
2. he/she forgave me for being late for the appointment,
3. and encouraged me, saying/thinking “let’s try again.”

This is a good example of Japanese stacking information before the final main verb.

Ending with くれた shows the speaker’s perspective more clearly.

Compare:

• 友達は…励ました。
  A plain statement: My friend encouraged me.
• 友達は…励ましてくれた。
  Adds warmth: My friend encouraged me for my sake / kindly encouraged me.

This nuance matters a lot in Japanese. The sentence is not just reporting an action; it also shows gratitude or appreciation toward the friend.

Yes, depending on context.

The て-form in 許して、また頑張ろうと励ましてくれた can suggest simple connection:

• forgave me and encouraged me

But it can also feel a little sequential:

• forgave me, then encouraged me

Both are reasonable. The exact English wording depends on what sounds most natural in context.

Because Japanese often omits participants that are easy to infer.

The listener already knows:

• the friend is the one doing the actions
• the speaker is the one being forgiven
• the speaker is also the one being encouraged

So Japanese does not need to repeat 私を.

This kind of omission is one of the most common differences from English.

Yes, it is natural and understandable.

It has several very common features of natural Japanese:

• a relative clause before a noun: 約束に遅れた私
• て-form linking: 許して
• quoted content with と: また頑張ろうと
• benefactive くれる: 励ましてくれた

So it is a very useful sentence for studying real Japanese structure.