haha wa yasai o itameru mae ni koshou o iresuginaide hoshii to watashi ni itta.

A helpful way to parse it is:

母は
→ As for my mother / My mother

野菜を炒める前に
→ before frying the vegetables

こしょうを入れすぎないでほしい
→ wanted someone not to add too much pepper

と
→ marks the quoted content

私に言った
→ said to me / told me

So the overall structure is:

My mother told me, “I want you not to add too much pepper before frying the vegetables.”

A more natural English translation might be:

My mother told me not to add too much pepper before stir-frying the vegetables.

は marks 母 as the topic of the sentence.

So 母は means something like:

• as for my mother
• or simply my mother in natural English

It tells us that the sentence is about what the mother did. In this case, what she did was 言った (said/told).

You could compare:

• 母は言った = My mother said... / As for my mother, she said...
• 母が言った = My mother is the one who said...

Here, は is the normal, neutral choice if you are just talking about your mother and what she said.

This is a very common question.

In Japanese, before 前に, the verb usually appears in the dictionary/plain non-past form when it means before doing X.

So:

• 野菜を炒める前に = before frying the vegetables

This does not mean before I will fry the vegetables in a literal future sense. It is just the normal grammar pattern:

• 食べる前に = before eating
• 寝る前に = before sleeping
• 出かける前に = before going out

By contrast:

• 炒めた後で = after frying

So:

• V-る 前に = before doing V
• V-た 後で = after doing V

前に means before.

In this sentence, it attaches to the whole action:

野菜を炒める前に
= before frying the vegetables

So the timing is:

1. first, do not add too much pepper
2. then fry the vegetables

It tells you when the mother wanted that action to happen.

This is made of several parts:

• 入れる = to put in / add
• 入れすぎる = to put in too much / add too much
• 入れすぎないで = don’t add too much / without adding too much
• 入れすぎないでほしい = I want you not to add too much

So V-ないでほしい is a pattern meaning:

I want you not to do V

Examples:

• 行かないでほしい = I want you not to go
• 忘れないでほしい = I want you not to forget
• 入れすぎないでほしい = I want you not to add too much

In this sentence, the mother is expressing that wish.

The person is 私 — me.

Even though Japanese often leaves subjects unstated, the sentence tells us:

• 母は ... 私に言った = My mother told me ...

And the quoted content is:

• こしょうを入れすぎないでほしい = I want you not to add too much pepper

So the understood meaning is:

My mother told me that she wanted me not to add too much pepper.

The person doing the wanting is the mother, and the person expected to avoid the action is the listener, me.

Because 言う uses に for the person you say something to.

So:

• 私に言った = said to me / told me

This is the normal pattern:

• A は B に 言う = A says to B
• 先生は学生に言った = The teacher said to the student
• 母は私に言った = My mother told me

を marks a direct object, but the person receiving speech is not the direct object of 言う. It is the target/recipient, so に is used.

と is the quotation particle.

It marks the content of what was said.

So:

• こしょうを入れすぎないでほしい と 私に言った = said to me, “I want you not to add too much pepper.”

This と can mark either:

• a direct quote
• or an indirect quote

In Japanese, the same structure is often used for both.

Other examples:

• 行くと言った = said “I’ll go” / said that he would go
• 静かにしてほしいと言った = said “I want you to be quiet”

It is related, but the grammar is a little different.

• 水がほしい = I want water
  Here, ほしい means want something

But in:

• 入れすぎないでほしい

the pattern is:

• V-てほしい = I want someone to do V
• V-ないでほしい = I want someone not to do V

So here ほしい is not about wanting a thing. It is about wanting someone’s action.

Compare:

• 手伝ってほしい = I want you to help
• 来ないでほしい = I want you not to come
• 入れすぎないでほしい = I want you not to add too much

Because Japanese often omits things that are understood from context.

If you spelled everything out, the meaning would be something like:

母は、私に、野菜を炒める前にこしょうを入れすぎないでほしいと言った。

Even here, the subject of 入れすぎないで is still not stated directly, but it is understood from the situation and from 私に言った.

Japanese frequently leaves out:

• I
• you
• he/she
• repeated nouns

This is very normal. Native speakers rely on context to identify who is doing what.

It comes from:

• 入れる = to put in / add
• 〜すぎる = to do too much / excessively

So yes, literally it is something like put in too much, but in natural English here it means:

• add too much
• put in too much

This 〜すぎる pattern is very common:

• 食べすぎる = eat too much
• 飲みすぎる = drink too much
• 話しすぎる = talk too much
• 入れすぎる = add too much

And then the negative:

• 入れすぎない = not add too much

Because 野菜 is still the direct object of 炒める.

So:

• 野菜を炒める = fry the vegetables

Then that whole verb phrase modifies 前:

• 野菜を炒める前に = before frying the vegetables

This is very normal in Japanese. A whole clause can come before a noun and describe it.

For example:

• 本を読む時間 = time to read a book / reading time
• 日本へ行く前に = before going to Japan
• 野菜を炒める前に = before frying the vegetables

So を is there because 野菜 belongs with 炒める, not with the main verb 言った.

Grammatically, Japanese with と can feel like either, depending on how you translate it.

So this could be understood as:

• direct-ish: My mother said to me, “Don’t add too much pepper before frying the vegetables.”
• indirect: My mother told me not to add too much pepper before frying the vegetables.

The Japanese sentence itself does not force the same distinction English does. It simply gives the content with と.

In natural English, the indirect version is usually smoother here: My mother told me not to add too much pepper before frying the vegetables.

When talking about your own mother to someone else, Japanese often uses 母.

• 母 = my mother / one’s mother when speaking humbly or neutrally about your own family
• お母さん = mom / mother, often when addressing her directly or referring to someone else’s mother more politely

So in narration, 母は ... 言った is very natural.

If you were talking to your mother, you would more likely say:

• お母さん

For example:

• お母さん、これ見て。 = Mom, look at this.

But when reporting about your own mother:

• 母は昨日帰りました。 = My mother came home yesterday.

Yes. A learner-friendly rewrite might be:

母は私に、野菜を炒める前にこしょうを入れすぎないでほしいと言った。

This version places 私に earlier, which may make the structure easier to see:

• 母は = my mother
• 私に = to me
• ...してほしい = wanted me to...
• 言った = said

The meaning stays the same. Japanese word order is flexible enough that both versions are natural.

A natural translation would be:

My mother told me not to add too much pepper before frying the vegetables.

If you want to preserve the want nuance of 〜ないでほしい, you could also say:

My mother told me that she wanted me not to add too much pepper before frying the vegetables.

But in everyday English, that sounds less natural. So the first version is usually best.