Este percurso é longo?

Because longo is being treated as a characteristic of the route itself, not a temporary condition.

• ser + adjective is commonly used for more inherent qualities: é longo, é curto, é difícil
• estar is usually for temporary states or conditions

So Este percurso é longo? sounds natural for asking whether the route is long in general.

No. In Portuguese, yes/no questions are usually formed just by intonation and a question mark, not by changing the word order.

So:

• Este percurso é longo. = statement
• Este percurso é longo? = question

The structure stays the same.

Este means this.

In traditional grammar:

• este = this, near the speaker
• esse = that, near the listener
• aquele = that over there, farther from both

In everyday Brazilian Portuguese, though, people often use esse where older rules might prefer este. So in real speech, Esse percurso é longo? is also very common.

Yes, but it can sound a bit more neutral or slightly formal than some other options.

Common related words:

• percurso = route, course, path taken
• trajeto = route/journey, very common
• caminho = way/path, often more everyday
• rota = route, especially in travel/navigation contexts

So this sentence is correct and natural, but in conversation you might also hear:

• Esse trajeto é longo?
• Esse caminho é longo?

They overlap, but there are small differences:

• percurso: the route or course taken; can sound slightly more formal or descriptive
• trajeto: the route from one place to another; very common for travel
• caminho: the way/path; often the most general and everyday

In many situations, all three could work, but the exact choice depends on context and style.

Both can relate to length, but longo is much more natural for things like routes, trips, periods of time, and distances in a broader sense.

• longo = long
• comprido = long in physical size/length, often for objects

So:

• um percurso longo = natural
• um percurso comprido = possible in some contexts, but less natural

For a route, longo is the usual choice.

Yes, depending on context.

longo can suggest:

• a long distance
• a route that feels long
• sometimes even a route that takes a long time

If you specifically want to talk about time, Portuguese often uses words like:

• demorado = time-consuming
• lento = slow

For example:

• Esse percurso é demorado? = Does this route take a long time?

A simple Brazilian Portuguese approximation is:

ES-che per-CUR-so eh LON-go?

A few notes:

• Este often sounds like ES-che in many Brazilian accents
• percurso has the stress on cur
• é is a clear open eh
• longo has stress on lon

Pronunciation varies by region, but that version will be understood.

No. When a noun is already introduced by a demonstrative like este, you normally do not add an article.

So:

• este percurso = correct
• o este percurso = incorrect

The demonstrative already does the job of specifying the noun.

Yes, absolutely.

Adding muito makes it stronger:

• Esse percurso é longo? = Is this route long?
• Esse percurso é muito longo? = Is this route very long?

That is a very natural variation.

Yes, but in everyday speech many Brazilians would more often say something like:

• Esse trajeto é longo?
• Esse caminho é longo?
• É longe? if the context is obvious

So your sentence is correct, but depending on the situation, a more conversational version might be more common.