kono sigoto ha hutuka de owaru hazu desu.

この is a determiner, so it must come before a noun: この仕事 = this job / this work.

これ is a standalone pronoun: this.

So:

• この仕事 = this job
• これ = this

You cannot normally say これ仕事.

は marks 仕事 as the topic of the sentence.

So この仕事は means something like:

• as for this job
• speaking of this work

It does not directly mark the subject in the same way English does. It sets up what the sentence is about, and then the rest of the sentence says something about it.

Here, the sentence is making a statement about this job: it is expected to finish in two days.

Here, 二日 is read ふつか.

This is an irregular reading, so it is something you simply need to memorize.

In this sentence, 二日 means two days.

A learner might know 二 = に and 日 = にち, but together this word is not read ににち here.

By itself, 二日 can mean either:

• two days
• the second day of the month

The meaning depends on context.

In this sentence, because it is followed by で and talks about how long the job takes, it means two days.

So here it is clearly a duration, not a date.

Here, で marks the amount of time needed to complete something.

So 二日で終わる means:

• to finish in two days
• to be completed within two days

This is a very common use of で with time spans.

It is different from other uses of で, such as:

• location of an action: 学校で勉強する
• means/tool: 箸で食べる

Here, it is specifically the time required.

Because 二日 here is a length of time, not a specific point in time.

• 二日で終わる = finish in two days / be done within two days
• 二日に終わる would sound like finish on the second day / on the 2nd

So で is used for the duration needed, while に would point to a specific time or date.

Yes, 二日間で is also possible.

• 二日で
• 二日間で

Both can mean in two days.

The version without 間 is very common and natural. Adding 間 just makes the duration a little more explicit.

So:

• 二日で終わる = natural
• 二日間で終わる = also natural, slightly more explicit about the time span

This is an important point.

• 終わる is intransitive: to end / to be finished
• 終える is transitive: to finish something

In this sentence, the focus is on the job itself reaching completion, so 終わる is natural:

• この仕事は二日で終わるはずです
  = This job should be finished in two days

If you used 終える, you would usually need someone who finishes it:

• この仕事を二日で終えるはずです
  = (Someone) should finish this job in two days

Japanese often uses an intransitive verb where English might use a passive expression like be finished.

Because はず attaches to the plain form of the verb.

So the pattern is:

• verb (plain form) + はずです

Examples:

• 行くはずです = should go / is expected to go
• 来るはずです = should come
• 終わるはずです = should finish / is expected to finish

So 終わりますはずです is incorrect.

The politeness comes from です, not from changing the verb to -ます form.

はずです expresses a strong expectation, usually based on some reason, plan, evidence, or common sense.

It often means:

• should
• is supposed to
• is expected to

So the speaker is not just guessing randomly. They believe this is what ought to happen based on some basis.

For example, maybe:

• the schedule says so
• the amount of work is reasonable for two days
• someone promised it would be done in two days

It is an expectation, not a guarantee.

Not usually.

はずです does not mainly express obligation. It expresses expectation.

So this sentence does not strongly mean:

• This job must be finished in two days

It more naturally means:

• This job should be finished in two days
• This job is expected to be done in two days

If you want real obligation, Japanese would use a different pattern, such as:

• 二日で終えなければなりません
• 二日以内に終わらせなければいけません

Those mean something closer to must finish within two days.

Japanese often leaves out the doer when it is obvious, unknown, or unimportant.

This sentence focuses on the result:

• the job should be finished in two days

It does not say who completes it, because that information is not necessary here.

In English, we often want a clear subject like we, they, or someone, but Japanese frequently omits that when the context already makes it clear enough.

はず behaves like a noun-like word, and です makes the sentence polite.

So:

• 終わるはずだ = plain / less polite
• 終わるはずです = polite

That is why the sentence ends with です, even though the verb before はず is in plain form.

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

So it would normally be written as:

この仕事は二日で終わるはずです。

Spaces are often added only in beginner materials to make the sentence easier to read.