Työ edistyy, kun suunnitelma on selkeä.

Edistyy is the 3rd person singular form of the verb edistyä, which means to progress, to advance, or to move forward.

So:

• edistyä = to progress
• edistyy = it progresses / is progressing

In this sentence, työ edistyy means the work progresses.

In Finnish, you usually do not need a separate subject pronoun if the subject is already stated.

Here:

• työ = work
• edistyy = progresses

So työ edistyy already means the work progresses.

Using a pronoun like se would usually only happen if you were referring back to something already mentioned and wanted to emphasize it or avoid repeating the noun.

Työ is the subject of the sentence, so it appears in the nominative (basic dictionary form).

• työ = work
• nominative singular = työ

Because the sentence is saying what the work does, työ is the thing performing the action of progressing.

Here, kun means when or if/whenever, depending on context.

In this sentence:

• Työ edistyy, kun suunnitelma on selkeä.

the most natural sense is something like:

• Work progresses when the plan is clear
• or Work progresses if the plan is clear

Finnish kun often introduces a time clause, but in practical use it can sometimes feel close to English when or if, especially in general statements.

Finnish has no articles, so there is no direct equivalent of a, an, or the.

That means:

• työ can mean work or the work
• suunnitelma can mean a plan or the plan

You figure out the exact meaning from context.

So:

• Työ edistyy = Work progresses or The work progresses
• suunnitelma on selkeä = the plan is clear or a plan is clear

In many example sentences, English uses the, but Finnish simply does not mark it.

Selkeä is an adjective meaning clear.

In this sentence:

• suunnitelma = plan
• on = is
• selkeä = clear

So suunnitelma on selkeä means the plan is clear.

It stays in the basic nominative singular form because it is a predicate adjective after the verb olla (to be).

Compare:

• selkeä suunnitelma = a clear plan
• suunnitelma on selkeä = the plan is clear

In both cases, singular nominative is used because suunnitelma is singular nominative.

On is the 3rd person singular form of olla (to be).

• olla = to be
• on = is

So:

• suunnitelma on selkeä = the plan is clear

This is a very common Finnish sentence pattern:

• X on Y = X is Y

Yes, the clauses can be reversed.

The original order is:

• Työ edistyy, kun suunnitelma on selkeä.
• Work progresses when the plan is clear.

You could also say:

• Kun suunnitelma on selkeä, työ edistyy.
• When the plan is clear, the work progresses.

Both are grammatical. The difference is mainly in emphasis:

• starting with Työ edistyy focuses first on the result
• starting with Kun suunnitelma on selkeä focuses first on the condition/circumstance

Edistyä is generally intransitive, meaning it does not take a direct object.

So:

• Työ edistyy = The work progresses

You do not say something like *työ edistyy jotain.

If you want a transitive verb meaning to promote, to advance something, or to make something progress, Finnish often uses edistää instead.

Compare:

• Työ edistyy. = The work progresses.
• Hyvä suunnitelma edistää työtä. = A good plan advances/promotes the work.

This is a very useful verb pair:

• edistyä = to progress
• edistää = to promote / advance something

Sometimes yes, but the meaning changes slightly.

• kun often means when and can also sound natural in general truths
• jos more clearly means if

Compare:

• Työ edistyy, kun suunnitelma on selkeä.
  Work progresses when the plan is clear.

• Työ edistyy, jos suunnitelma on selkeä.
  Work will progress if the plan is clear.

The version with kun sounds a bit more like a general observation or principle.
The version with jos sounds more like a condition.

Finnish does not have a separate future tense the way English does.

The present tense is often used for:

• present actions
• general truths
• future events, if the context makes it clear

So Työ edistyy, kun suunnitelma on selkeä can express a general truth without needing a special future form.

Depending on context, English might translate it as:

• Work progresses when the plan is clear
• The work will progress when the plan is clear

Finnish uses the same present-tense forms and lets context do the rest.

Yes. Selkeä often means more than just visually or intellectually clear. It can also mean:

• well-defined
• unambiguous
• easy to understand
• organized in a clear way

So suunnitelma on selkeä could imply that the plan is:

• easy to understand
• logically structured
• specific enough to guide the work

That broader sense is often important in Finnish.

Yes, most likely.

The sentence sounds like a general truth or principle:

• Work progresses when the plan is clear.

It is not necessarily describing one exact moment right now. Finnish present tense often covers this kind of broad statement.

If you wanted to make it sound more tied to a specific current situation, context would usually do that rather than changing the grammar very much.