kyou ha hayaku syukkinsimasita.

Here, 今日 is read きょう.

This is the most common reading when it means today in everyday speech.
Other readings of the same kanji exist in other words, such as こんにち, but not in this sentence.

は marks 今日 as the topic of the sentence.

So 今日は means something like:

• as for today
• today, ...

It sets the time frame for what follows. In Japanese, time expressions are often followed by は when the speaker wants to make them the topic or give them a little emphasis.

Yes, it can.

You can say:

• 今日は早く出勤しました。
• 今日早く出勤しました。

Both are natural. The version with は sounds a bit more like speaking about today in particular. Without は, it is a little more neutral and straightforward.

Because 早い is an い-adjective, and when an い-adjective modifies a verb, it usually changes to its adverb form.

So:

• 早い = early / fast
• 早く = early / quickly, in a way that modifies a verb

Since 出勤しました is a verb, you need 早く.

In this sentence, it means early, not quickly.

That is because 出勤する means to go to work / report to work, so 早く出勤しました means the person went to work at an early time.

In other contexts, 早く can mean quickly, so the exact meaning depends on the verb and the situation.

出勤する means to go to work, to report for work, or to commute to work.

It is more specific than just 行く. It focuses on the act of going to one's workplace for work.

Compare:

• 会社に行きました = went to the company / office
• 出勤しました = went to work / reported for work

出勤する is a very common word in workplace Japanese and sounds a bit more formal or job-related than just 行く.

Because 出勤しました is the polite past form.

The base verb is:

• 出勤する

Its past forms are:

• 出勤した = plain past
• 出勤しました = polite past

So this sentence is in polite style, which is common in textbooks and everyday polite conversation.

Because 出勤する is a noun + する verb.

• 出勤 = attendance at work / going to work
• する = to do

Many Japanese verbs are built this way. When you conjugate them, you actually conjugate する.

So:

• 出勤する
• 出勤します
• 出勤しました

That is why you see しました at the end.

The subject is omitted because Japanese often leaves out information that is clear from context.

In a sentence like this, the understood subject is often:

• I
• we
• or another person already being discussed

In many natural Japanese sentences, you do not need to say the subject if the listener can figure it out.

Because 早く is functioning as an adverb, and adverbs usually do not need particles before the verb they modify.

So this pattern is normal:

• 早く出勤しました
• ゆっくり話しました
• 静かに歩きました

The adverb directly modifies the verb.

Because 出勤する already contains the idea of going to work.

The workplace or destination can be left unstated if it is obvious. So 出勤しました by itself is complete.

If you want to name the workplace, you can add it:

• 会社に出勤しました
• 東京支社に出勤しました

But it is not necessary when the destination is understood.

Yes, it is natural.

今日は早く出勤しました。 is a normal, natural way to say that someone went to work early today.

It sounds like something you might say in conversation, a diary entry, or a workplace context.

Yes, and that changes the focus slightly.

• 今日は早く出勤しました = focuses on today
• 今朝は早く出勤しました = focuses on this morning

Since going to work usually happens in the morning, 今朝 can sound very natural if you specifically want to talk about the morning rather than the whole day.

Japanese word order is somewhat flexible, but not completely free.

The most natural order here is:

• 今日は早く出勤しました。

You may also hear:

• 今日早く出勤しました。

But moving things around too much can sound unnatural. As a beginner, it is safest to keep:

time expression + adverb + verb

That pattern works very well here.

This is a good question because 早い can relate to both early and fast, depending on context.

In this sentence, it clearly means early, because 出勤する is about the time someone goes to work, not the speed of movement.

So here:

• 早く = at an early time

not

• quickly

They are different actions.

• 出勤しました = went to work / showed up for work
• 働きました = worked

So 出勤しました focuses on going in to work, while 働きました focuses on doing the work itself.

A person could 出勤する without necessarily saying anything about how much they actually worked.

It might, depending on the situation.

出勤する usually implies physically going to a workplace. If someone works from home, 在宅勤務しました or another expression may be more natural.

So 出勤しました usually suggests commuting or showing up at the workplace, not remote work.