La aŭto turniĝas malrapide ĉe tiu angulo.

In Esperanto, turni is normally used as a transitive idea: you turn something.

• Mi turnas la radon = I turn the wheel.

If you want to say that the subject itself changes direction, Esperanto very often uses turniĝi.

• La aŭto turniĝas = the car turns / is turning.

So La aŭto turnas by itself would sound unfinished, as if the car is turning something else.

-iĝ- often means to become, to get into a state, or to undergo a change.

So:

• turni = to turn something
• turniĝi = to turn oneself / to become turned / to change direction

In this sentence, turniĝas shows that the car itself is undergoing the turning movement.

Yes, but it is less natural here.

• turnas sin literally means turns itself
• turniĝas is the usual, smoother Esperanto way to express that something turns

With a car changing direction, turniĝas is the normal choice.

Because it modifies the verb, not the noun.

• malrapida aŭto = a slow car
• turniĝas malrapide = turns slowly

In Esperanto:

• -a = adjective, used for nouns
• -e = adverb, used for verbs, adjectives, or whole clauses

So malrapide is correct because it describes how the car turns.

mal- is a very common Esperanto prefix meaning the opposite of.

• rapida = fast
• malrapida = slow
• malrapide = slowly

Esperanto often makes opposites this way instead of using a completely different root.

la is Esperanto’s definite article, meaning the.

• la aŭto = the car
• aŭto = a car / car

Esperanto has no indefinite article like English a/an. So if you want an indefinite meaning, you usually just leave out la.

ĉe usually means at, by, near, or in the area of.

So ĉe tiu angulo means something like:

• at that corner
• by that bend
• at that point/angle

It tells you the place where the turning happens.

Because ĉe is better for a location understood as a point or spot.

• ĉe = at/by/near
• en = in/inside

A car is not really inside a corner, so en tiu angulo would usually sound less natural here. ĉe tiu angulo is the more idiomatic choice for at that corner/bend.

Yes, angulo literally means angle, but it can also refer to a corner or a sharp turning point in context.

So here it can naturally be understood as:

• a corner in the road
• a bend
• a turning point

Depending on context, Esperanto speakers may also use words like kurbo for a curve, but angulo is understandable for a corner-like turn.

Because tiu is the form used before a noun.

• tiu angulo = that corner
• tio = that thing

So:

• tiu = demonstrative adjective
• tio = demonstrative pronoun

Since angulo is present, you need tiu.

It can mean either, depending on context.

Esperanto -as is the present tense, but it does not force the same distinction English makes between:

• turns
• is turning

So turniĝas can mean:

• turns slowly at that corner
• is turning slowly at that corner

Usually the surrounding context makes the intended meaning clear.

Because there is no direct object here.

• La aŭto is the subject
• turniĝas is the verb
• malrapide is an adverb
• ĉe tiu angulo is a prepositional phrase

The accusative -n is mainly used for direct objects and for some motion expressions. This sentence does not need it.

Not completely. Esperanto word order is fairly flexible, because endings do a lot of the grammatical work.

This sentence has a neutral order:

• La aŭto turniĝas malrapide ĉe tiu angulo.

But other orders are possible for emphasis, for example:

• Malrapide la aŭto turniĝas ĉe tiu angulo.
• Ĉe tiu angulo la aŭto turniĝas malrapide.

The basic meaning stays the same, but the emphasis changes.

The special sounds are:

• aŭ in aŭto: like the ow sound in cow
• ĝ in turniĝas: like j in judge
• ĉ in ĉe: like ch in church

Also remember that Esperanto stress is normally on the second-to-last syllable:

• AŬ-to
• tur-NI-ĝas
• mal-ra-PI-de
• an-GU-lo