watasi ha kono sigoto ni sekinin wo motte imasu.

は marks 私 as the topic of the sentence. It sets up as for me...

So:

• 私は = as for me / I
• 私が would sound different; it would emphasize I as the person responsible, often in contrast to someone else.

In this sentence, は is the most natural choice if you are simply stating your responsibility.

In 仕事に責任を持つ, the particle に marks the thing that the responsibility is directed toward.

So:

• この仕事に = for this job / regarding this work
• 責任を持つ = to have/take responsibility

This is just the normal pattern for this expression:

• A に 責任を持つ = to be responsible for A

Even though English uses for, Japanese uses に here.

Both can relate to responsibility, but they are not exactly the same.

• 責任がある = to have responsibility / to be responsible
• 責任を持つ = to take/assume responsibility, with a slightly stronger sense of actively bearing it

So この仕事に責任を持っています sounds like:

• I am taking responsibility for this work
• I am responsible for this job

It can feel a little more active and intentional than 責任があります.

Yes, 持つ literally means to hold / to have, but in this sentence it is part of the fixed expression 責任を持つ.

So here it does not mean physically holding something.
It means:

• to take responsibility
• to be responsible

This kind of idiomatic use is very common in Japanese.

持っている is the ている form of 持つ.

With many verbs, ている can show:

• an ongoing action, or
• a continuing state

In this expression, 責任を持っている usually describes a continuing state:

• I am responsible
• I have responsibility

Comparison:

• 責任を持つ = dictionary form, general statement
• 責任を持っています = polite, current state: I am responsible

Yes. 持っています is polite because it ends with います in the ます style.

Compare:

• 責任を持っている = plain form
• 責任を持っています = polite form

So this sentence is polite overall, even though it does not end with です.

Yes, very often.

Japanese frequently leaves out subjects when they are clear from context. So in a real conversation, people might simply say:

• この仕事に責任を持っています。

That can still mean I am responsible for this work, if the context makes that obvious.

Including 私 can add clarity or emphasis, but it is not always necessary.

仕事 can mean several related things, including:

• job
• work
• task
• assignment

In この仕事, it usually means this piece of work / this task / this job, depending on context.

So the sentence could mean:

• I am responsible for this task
• I am responsible for this work
• I am responsible for this job

It does not always mean your profession in the broad sense.

Yes, Japanese word order is more flexible than English word order, as long as the particles stay attached to the right words.

Standard version:

• 私はこの仕事に責任を持っています。

Other possible orders:

• この仕事に私は責任を持っています。
• 私は責任をこの仕事に持っています。 ← grammatically possible, but less natural

The most natural order is usually the original one, because it flows cleanly from topic to target to object to verb.

を marks 責任 as the direct object of 持つ.

So grammatically, Japanese treats it as:

• responsibility = the thing being held
• 持つ = to hold / have

That is why the pattern is:

• 責任を持つ

Even though the full English meaning is to be responsible for..., Japanese builds it as to hold responsibility.

No, normal Japanese is usually written without spaces.

A natural written version would be:

• 私はこの仕事に責任を持っています。

Spaces are often added only in teaching materials to help learners see the parts of the sentence more easily.

責任 is read せきにん.

So the full sentence is read:

• わたし は この しごと に せきにん を もっています。

In normal writing without spaces:

• わたしはこのしごとにせきにんをもっています。

Yes, it is natural and correct.

It sounds like a straightforward, polite statement that you are responsible for some work or assignment.

Depending on context, a native speaker might also say:

• 私はこの仕事の責任者です。 = I am the person in charge of this job.
• この仕事は私が責任を持っています。 = I’m the one responsible for this job.

But your original sentence is perfectly natural.