gyoumu ha muzukasii desu.

は marks 業務 as the topic of the sentence.

So the sentence is structured like:

• 業務 = duties / work tasks / operations
• は = as for...
• 難しいです = is difficult

A natural way to think of it is:

• As for the work duties, they are difficult.

In English, we often just say The work is difficult, but Japanese often organizes sentences by topic first.

難しい is an i-adjective.

For i-adjectives, you can attach です directly for politeness:

• 難しい = difficult
• 難しいです = difficult (polite)

You do not use な with an i-adjective, and だです is incorrect.

Compare:

• 静かです = quiet (because 静か is a na-adjective)
• 難しいです = difficult (because 難しい is an i-adjective)

So 難しいです is the correct polite form.

Yes, you can, but the nuance changes.

• 業務は難しいです
  = As for the duties, they are difficult / The duties are difficult
• 業務が難しいです
  = The duties are difficult with more focus on what is difficult

Very roughly:

• は = topic / contrast / general statement
• が = identifies or emphasizes the subject

If you are just making a neutral statement, 業務は難しいです is very natural.
If you are answering a question like What is difficult?, then 業務が難しいです may fit better.

Not exactly.

業務（ぎょうむ） is a more formal, business-like word. It often means:

• duties
• operations
• work responsibilities
• official tasks

仕事（しごと） is broader and more common in everyday speech:

• work
• job
• task

So:

• 仕事は難しいです sounds more everyday
• 業務は難しいです sounds more formal or workplace-related

In an office, company, or administrative context, 業務 is very natural.

Yes, it is grammatical and natural, especially in a formal or workplace context.

Because 業務 is a formal word, the sentence sounds like something you might hear in:

• business settings
• reports
• training
• workplace conversation

In casual daily speech, a person might more often say:

• 仕事は難しいです。
• この仕事は難しいです。

But 業務は難しいです is still perfectly good Japanese.

It is pronounced:

• ぎょうむ
• Romanization: gyoumu

Breakdown:

• ぎょ = gyo
• う lengthens the o sound, so ぎょう is like a long gyo/gyo-o
• む = mu

So it sounds roughly like gyoh-moo, though Japanese pronunciation is smoother and shorter than English.

Also:

• 業 = ぎょう
• 務 = む

Normally, Japanese is written without spaces.

So the usual writing is:

• 業務は難しいです。

The spaced version:

• 業務　は　難しい　です。

is often used only for learners, textbooks, or grammar explanations to make the parts easier to see.

In real Japanese writing, you should usually write it without spaces.

難しい is an i-adjective.

A quick sign is that it ends in い in its dictionary form.

That matters because i-adjectives change differently from nouns and na-adjectives.

Examples:

• 難しい = difficult
• 難しくないです = not difficult
• 難しかったです = was difficult
• 難しくなかったです = was not difficult

So in this sentence, 難しい is the word describing 業務.

Mostly, yes, but it can also carry nuances like:

• hard
• challenging
• complex
• not easy

Depending on context, 難しい can describe:

• a task that is hard to do
• a concept that is hard to understand
• a situation that is delicate or complicated

So in 業務は難しいです, it could mean:

• the duties are difficult
• the work is complicated
• the operations are challenging

The exact nuance depends on context.

Yes. The plain form would be:

• 業務は難しい。

This sounds less polite and more direct.

Compare:

• 業務は難しいです。 = polite
• 業務は難しい。 = plain

The meaning is basically the same, but です makes it more polite and suitable for normal conversation, workplace speech, or careful statements.