När jag är klar med jobbet, går jag hem.

Because Swedish main clauses follow the V2 rule: the finite verb comes in the second position.

Here, the whole first part När jag är klar med jobbet takes the first position. So the verb of the main clause, går, must come next, before the subject jag:

• När jag är klar med jobbet, går jag hem.

If the sentence started directly with the subject, then you would say:

• Jag går hem.

Because När jag är klar med jobbet is a subordinate clause, not a question.

In Swedish subordinate clauses, the normal order is usually:

• conjunction + subject + verb

So:

• När jag är klar... = When I am done...

But:

• När är jag klar? = When am I done?

That second one is a direct question.

Here när means when.

Depending on context, it can mean:

• when in a specific future situation
• or whenever in a habitual situation

So this sentence can mean either:

• When I’m done with work, I go home
• or When I’m done with work, I’ll go home

The exact meaning depends on the situation.

Swedish often uses the present tense for future meaning, especially after time words like när.

This is similar to English:

• When I’m done, I’ll go home
• not When I will be done...

In Swedish, present tense can cover:

• a routine: When I’m done with work, I go home
• a future event: When I’m done with work, I’ll go home

Context tells you which one is meant.

Klar can mean ready, finished, or done, depending on context.

In this sentence:

• är klar med jobbet

it means am finished with the work or am done with work.

So klar is not just about being prepared; it can also mean that something has been completed.

Because klar med is a common Swedish expression meaning finished with.

So:

• Jag är klar med jobbet = I’m done with the work / job

The preposition med is just part of the normal pattern here. It is best learned as a chunk:

• klar med något = done with something

Jobbet is the definite form of jobb, so literally it means the job or the work.

Swedish often uses the definite form where English might simply say work:

• Jag är på jobbet = I’m at work
• Jag är klar med jobbet = I’m done with work

Using just jobb here would sound unnatural or incomplete.

Because hem by itself often means home in the sense of toward home.

So:

• gå hem = go home

You do not say till hem.

A useful comparison is:

• Jag går hem. = I’m going home.
• Jag är hemma. = I’m at home.

So hem is directional, while hemma is location.

Not always.

In modern Swedish, a comma after an introductory subordinate clause is often optional, especially in shorter sentences. So both of these can be seen:

• När jag är klar med jobbet, går jag hem.
• När jag är klar med jobbet går jag hem.

The version without the comma is very common.

Yes. Some common alternatives are:

• När jag har jobbat klart går jag hem.
  Slightly more focused on the action of working.

• När jag är klar med arbetet går jag hem.
  More formal, because arbetet is more formal than jobbet.

• Efter jobbet går jag hem.
  Means After work, I go home, which is close but not exactly the same wording.

All of these are natural, but När jag är klar med jobbet, går jag hem. is perfectly understandable.