dousite kyou ha sonnani isoide iru ndesu ka?

は marks 今日 as the topic: as for today.

So the sentence has a nuance like why are you in such a hurry today, specifically? It can sound as if today is a little unusual compared with other days.

A time word like 今日 can sometimes appear without a particle, so どうして今日そんなに急いでいるんですか is also possible. Using は just gives 今日 a bit more focus or contrast.

どうして is a common way to say why? or how come?

Compared with similar words:

• どうして: neutral and common in conversation
• なんで: more casual
• なぜ: more formal, more written, or more serious-sounding

So どうして fits very naturally in a polite spoken question like this.

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

Here it modifies 急いでいる, so it means something like:

• being in such a hurry
• hurrying that much
• rushing so much

Without そんなに, the question would still work, but そんなに adds the idea that the speaker thinks the other person's rushing seems noticeable or stronger than usual.

急ぐ is the dictionary form: to hurry.

急いでいる is て-form + いる, which often shows an ongoing action or current state. In this sentence, it means the person is currently hurrying or is in a hurry.

So:

• 急ぐ = to hurry
• 急いでいる = is hurrying / is in a hurry

Using 急ぐ by itself here would not sound right for this kind of what are you doing right now? question.

急ぐ is a godan verb ending in ぐ. For verbs ending in ぐ, the て-form changes like this:

• ぐ → いで

So:

• 急ぐ → 急いで

This is the same pattern as:

• 泳ぐ → 泳いで
• 脱ぐ → 脱いで

Then you add いる:

• 急いで + いる → 急いでいる

んです adds an explanatory or seeking-an-explanation tone.

So this sentence is not just a plain factual question. It sounds more like:

• How come you're in such a hurry today?
• Why are you in such a hurry today?

The speaker feels there is some reason behind it and is asking for that reason.

Compare:

• どうして今日はそんなに急いでいますか。
  = more straightforward, plain polite question

• どうして今日はそんなに急いでいるんですか。
  = more natural in conversation when asking for background or explanation

Because んです attaches to the plain form of the verb, not the polite ます form.

So:

• 急いでいるんですか = correct
• 急いでいますか = also correct, but different nuance
• 急いでいますんですか = incorrect

This is a very common pattern in Japanese:

• 食べるんです
• 行くんです
• 忙しいんです

Even though the verb before んです is plain, the whole sentence is still polite because of です and か.

か marks the sentence as a question.

In polite Japanese, putting か at the end is the standard way to ask a question:

• 〜ですか
• 〜ますか
• 〜いるんですか

In casual speech, people often ask questions just with rising intonation and no か, but in a polite sentence like this, か is very normal.

Japanese usually puts the verb near the end, and things like time words and adverbs come before it.

This sentence is roughly arranged like this:

• どうして = why
• 今日 は = as for today
• そんなに = so much / that much
• 急いでいる = are hurrying / are in a hurry
• んですか = explanatory question

So Japanese builds up the situation first and saves the main verb for later. That is very normal in Japanese.

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

So this would normally be written as:

どうして今日はそんなに急いでいるんですか？

Spaces are often added only in learning materials to make the structure easier to see.