Não te desvies do percurso.

Because this is a negative command addressed to tu in European Portuguese.

With tu, affirmative and negative commands are formed differently:

• Affirmative: usually uses the imperative form
  
  • Desvia-te do percurso. = Don’t stray from the route.
• Negative: uses não + present subjunctive
  
  • Não te desvies do percurso.

So desvies is the present subjunctive form of desviar-se, used here because the command is negative.

Te is the object/reflexive pronoun for tu.

The verb here is desviar-se, which is often used reflexively to mean things like:

• to stray
• to deviate
• to move away from one’s path

In European Portuguese, pronoun placement changes depending on the structure:

• Affirmative command: Desvia-te
• Negative command: Não te desvies

The word não triggers proclisis, which means the pronoun goes before the verb.

So:

• Desvia-te
• Não te desvies

This is a very common pattern in Portuguese.

Yes, it is being used pronominally/reflexively here.

The base verb is desviar, which can mean to divert, to move aside, or to deflect something.
When used as desviar-se, it often means:

• to turn away
• to deviate
• to stray

So te shows that the subject you is the one moving off course.

Compare:

• Desviar o carro = to steer the car aside
• Desviar-se do caminho = to stray from the path

In this sentence, te is an essential part of the natural expression.

Do is a contraction of:

• de
  • o = do

So:

• do percurso = from the route / off the route / from the path

Portuguese very often contracts de with articles:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

This happens all the time, so it is worth getting used to early.

Because the verb pattern here is desviar-se de alguma coisa — to deviate from something.

So the preposition de is required:

• desviar-se do percurso
• desviar-se do caminho
• desviar-se da rota

Without de, the sentence would sound incomplete or ungrammatical in this meaning.

Percurso means something like:

• route
• course
• itinerary
• set path

It is often a bit more formal or specific than caminho.

A rough comparison:

• caminho = path/way/road in a broad, everyday sense
• percurso = a route or course that has been laid out or followed

So Não te desvies do percurso can sound slightly more like:

• stay on the designated route
• don’t go off the planned course

Whereas Não te desvies do caminho is also very natural, but a bit more general.

It is informal singular, because it is addressed to tu.

The clues are:

• te = pronoun for tu
• desvies = subjunctive form used for a negative command with tu

If you wanted a more formal version, using você, it would be:

• Não se desvie do percurso.

If you wanted the plural informal form (vocês), it would be:

• Não se desviem do percurso.

So the original sentence is what you would say to one person you address as tu.

No — it would mean the opposite.

• Desvia-te do percurso. = Stray from the route / Move off the route.
• Não te desvies do percurso. = Don’t stray from the route.

The não completely changes the meaning.

Also notice the pronoun position changes:

• Desvia-te
• Não te desvies

That shift is very important in Portuguese.

Because desvies is the tu form of the present subjunctive of desviar-se.

The verb is desviar.
For the present subjunctive, you start from the eu form of the present indicative:

• eu desvio

Then remove the -o and add the subjunctive endings:

• que eu desvie
• que tu desvies
• que ele/ela/você desvie
• que nós desviemos
• que vós desvieis
• que eles/elas/vocês desviem

So desvies is exactly what you expect for tu.

No. That word order is wrong.

In a negative sentence, the pronoun must come before the verb:

• Não te desvies do percurso. ✅

Not:

• Não desvies-te do percurso. ❌

In European Portuguese, this is a key rule:

• Affirmative command: pronoun after the verb
  
  • Desvia-te
• Negative command: pronoun before the verb
  
  • Não te desvies

The same sentence is understandable in Brazil, but pronoun use often differs.

In Brazilian Portuguese, people often prefer:

• Não se desvie do percurso.
• Não desvie do percurso.
• Não saia do percurso.

Using tu with te and desvies is much more characteristically European Portuguese, although some regions in Brazil also use tu.

So for a learner of Portuguese from Portugal, Não te desvies do percurso is a very natural European Portuguese sentence.

Yes. Depending on context, native speakers might also say:

• Não saias do caminho.
• Não te afastes do caminho.
• Mantém-te no percurso.
• Fica no caminho certo.

The original sentence is perfectly correct and natural, but percurso can sound a little more like a marked route, trail, or planned course.

So the best choice depends on the situation:

• hiking trail
• driving directions
• instructions in a game
• figurative advice

It can be used both literally and figuratively.

Literal:

• staying on a path, trail, route, or road

Figurative:

• not losing focus
• not departing from a plan
• not going off track in life, work, or study

Because percurso can also suggest a course or trajectory, it works quite well in figurative language too.

So depending on context, it could mean something like:

• don’t go off the route
• don’t deviate from the plan
• stay on course

In European Portuguese, it is roughly pronounced like duzh-VYEZH or duzh-VYESH, depending on the speaker and accent.

A few helpful points:

• des- often sounds closer to duzh in connected European Portuguese speech
• vi sounds like vyee
• the final -es in this form often sounds like zh or sh depending on the phonetic environment and accent

You do not need to pronounce every written vowel clearly the way you might in Spanish. European Portuguese often reduces unstressed vowels quite a lot.

So the whole sentence may sound more compressed than you expect from the spelling.