sonna ni isoganakute mo daizyoubu desu.

そんなに means something like that much, so much, or to that extent.

In this sentence, そんな points to a degree or extent, and に turns it into an adverb-like expression modifying the verb 急ぐ (to hurry).

So:

• そんな = that kind of / that sort of / that much
• そんなに = to that extent / that much

A very natural English equivalent here is You don’t have to hurry that much or There’s no need to rush so much.

It comes from the verb 急ぐ (to hurry).

Step by step:

• 急ぐ
• negative form: 急がない = do not hurry
• 〜ない changes to 〜なくて
• then add も

So:

• 急がない → 急がなくて
• 急がなくても

This pattern verb-negative-te-form + も often means even if you don’t... or, in many common situations, you don’t have to...

So 急がなくても means even if you don’t hurry / you don’t need to hurry.

Here, も adds the sense of even.

So literally, 急がなくても大丈夫です is close to:

• Even if you don’t hurry, it’s okay.

That is why the whole sentence naturally becomes:

• You don’t have to hurry.
• It’s okay if you don’t hurry so much.

This 〜なくてもいい / 〜なくても大丈夫 pattern is very common for saying something is not necessary.

Both can express that something is okay, but the nuance is a little different.

• 〜なくてもいいです = you don’t have to... / it’s fine not to...
• 〜なくても大丈夫です = it’s okay even if you don’t... / there’s no problem if you don’t...

大丈夫 often sounds a little more reassuring. It gives the feeling of Don’t worry, it’ll be fine.

So 急がなくても大丈夫です feels a bit softer and more comforting than a plain 急がなくてもいいです.

Grammatically, it is closer to:

• Even if you don’t hurry, it’s okay.

But in natural English, that usually becomes:

• You don’t need to hurry.
• There’s no need to rush.

So both ideas are connected. The Japanese structure focuses on it being okay not to do something, while English often expresses that as not needing to do it.

Because this is the grammar pattern based on the negative form of the verb, not the -te form of the affirmative verb.

Compare:

• 急ぐ = to hurry
• 急いで = hurrying / hurry and...
• 急がない = do not hurry
• 急がなくて = not hurrying / without hurrying / if not hurrying

For you don’t have to hurry, Japanese uses the negative-based pattern:

• 急がなくてもいい
• 急がなくても大丈夫

So 急いでなくて is not the form you want here.

Yes.

• 急がなくても大丈夫です = You don’t need to hurry.
• そんなに急がなくても大丈夫です = You don’t need to hurry that much. / You don’t have to rush so much.

Adding そんなに makes the sentence more specific. It softens the urgency by saying the person is hurrying more than necessary.

Not always, but it often appears in sentences involving degree, especially with negatives or comments about excess.

For example:

• そんなに高くないです。 = It’s not that expensive.
• そんなに心配しなくてもいいです。 = You don’t have to worry that much.

It can also be used positively depending on context, but in many everyday sentences it often means that much in a way that comments on intensity.

It is polite because it ends in です.

Tone-wise, it sounds:

• polite
• gentle
• reassuring

It would be appropriate in many everyday situations, such as speaking to:

• a customer
• a coworker
• someone you do not know well
• an older person, depending on context

More casual versions include:

• そんなに急がなくても大丈夫。
• そんなに急がなくていいよ。

A more formal version could be:

• そんなにお急ぎにならなくても大丈夫です。

そんな belongs to the so-/that kind group that often relates to something associated with the listener or with what has just been mentioned.

The rough pattern is:

• こんな = like this / this kind of
• そんな = like that / that kind of
• あんな = like that over there / that kind of

In real conversation, そんなに often means that much based on the current situation or on what the other person is doing.

So if someone is obviously rushing, そんなに急がなくても大丈夫です means You don’t need to rush that much.

It is mainly reassurance, but depending on tone and context, it can also gently imply:

• Please don’t rush so much.
• Take your time.

So the core meaning is It’s okay; there’s no need to hurry, but the practical effect can be to calm the other person down or encourage them to slow down.

It is softer than a direct command like:

• 急がないでください。 = Please don’t hurry.

Yes, it is very similar.

• そんなに急がなくても大丈夫です
• それほど急がなくても大丈夫です

Both mean roughly You don’t have to hurry that much.

Nuance difference:

• そんなに is very common and conversational.
• それほど can sound a bit more formal or measured.

In everyday speech, そんなに is extremely natural.