haha no hanasi wo kiite, taisetuna yakusoku wo omoidasimasita

Japanese often leaves out the subject when it is obvious from context.

So in 母の話を聞いて、大切な約束を思い出しました, the speaker is understood to be the one who listened and remembered, even though I is not stated.

A very natural English translation includes I, but the Japanese sentence does not need it.

母（はは） means my mother when speaking about your own mother in a neutral or humble way.

お母さん is more like:

• mom
• mother
• or how you refer to someone else’s mother politely

So in this sentence, 母 is the normal choice if the speaker is talking about their own mother.

母の話 literally means mother’s talk/story.

In natural English, it could mean:

• what my mother said
• my mother’s story
• my mother’s talk

Here, it most likely means what my mother was saying or my mother’s words/story.

The particle の connects 母 and 話, showing that the 話 belongs to or is related to the mother.

The particle を marks the direct object of the verb.

Here:

• 話を聞く = to listen to a story / to hear what someone says

So 母の話を聞いて means listening to my mother’s story or after hearing what my mother said.

Even though English uses to in listen to, Japanese uses を with 聞く in this kind of sentence.

聞いて is the て-form of 聞く.

The て-form has many uses. In this sentence, it connects two actions:

1. 母の話を聞いて
2. 大切な約束を思い出しました

So it means something like:

• I listened to my mother, and then...
• After hearing my mother’s words,...
• Hearing my mother’s story, ...

It shows that the first action leads into the second.

It can suggest more than one of those ideas, depending on context.

In this sentence, 聞いて most naturally means:

• after hearing
• or on hearing

It connects the events smoothly, and it can also imply that hearing the mother’s words triggered the memory.

So the nuance is close to: After hearing my mother talk, I remembered an important promise.

大切 is a na-adjective, not an i-adjective.

So before a noun, it becomes:

• 大切な約束 = an important promise

Compare:

• 高い山 = a high mountain (i-adjective)
• 静かな部屋 = a quiet room (na-adjective)
• 大切な約束 = an important promise (na-adjective)

That is why な appears before 約束.

約束（やくそく） means promise.

So 大切な約束 means:

• an important promise
• a precious promise

It can refer to a promise made to someone, or sometimes an appointment depending on context, but here promise is the most natural meaning.

Because 約束 is the object of 思い出しました.

The pattern is:

• 約束を思い出す = to remember a promise

So:

• 大切な約束を思い出しました = remembered an important promise

The particle を marks what was remembered.

思い出しました is the polite past form of 思い出す, which means to remember, to recall, or to have something come back to mind.

This verb often suggests that something was forgotten or not actively in your mind, and then you suddenly remembered it.

So it is a very good match for:

• I remembered
• It came back to me

It is different from simply already knowing or remembering something continuously.

Because the sentence describes a completed event: the speaker heard the mother’s words and then remembered the promise.

So 思い出しました means:

• remembered
• came to remember

The polite ending ました also makes the sentence sound formal or neutral-polite.

Japanese sentences usually place the main verb at the end.

So the structure is roughly:

• 母の話を聞いて = after hearing my mother’s story
• 大切な約束を = an important promise
• 思い出しました = remembered

This final-verb structure is one of the biggest differences from English word order.

Here, 話 is read はなし.

So:

• 母の話 = はは の はなし

This word can mean story, talk, or what someone said, depending on context.

Yes, that nuance is possible.

The て-form can sometimes imply a causal relationship, not just a simple sequence. So the sentence can suggest that hearing the mother’s words caused the memory to come back.

That said, the most straightforward understanding is:

• After hearing my mother’s story, I remembered an important promise.

The cause-and-effect feeling is there, but it is not heavily emphasized.

Yes. 聞く（きく） is the normal verb for:

• hear
• listen
• ask

In this sentence, it means to listen to / hear.

Japanese does not always separate hear and listen as strictly as English does, so 聞く is very common here.

You may also see 聴く, which can be used for carefully listening, especially to music or something more intentional, but 聞く is the standard everyday choice.