Agteruitry tydens parallelle parkering is moeilik.

Because in this sentence it functions like a single noun meaning reversing or driving backwards.

Afrikaans often joins words together in compounds. Here:

• agteruit = backwards / in reverse
• ry = drive / ride

As a normal verb phrase, you can separate them:

• Ek ry agteruit. = I am reversing.

But when the idea becomes a noun-like activity, Afrikaans commonly writes it as one word:

• Agteruitry is moeilik. = Reversing is difficult.

So agteruitry here works a bit like English reversing.

It is functioning as a noun.

Even though it comes from the verb ry, the whole word agteruitry names an activity, so it acts as the subject of the sentence:

• Agteruitry = the activity
• is = is
• moeilik = difficult

So grammatically, it behaves like Swimming in Swimming is hard.

Tydens means during. It introduces a noun phrase:

• tydens parallelle parkering = during parallel parking

By contrast, terwyl means while and usually introduces a full clause:

• terwyl ek parallel parkeer = while I parallel park

So in this sentence, tydens is used because it is followed by the noun phrase parallelle parkering, not a full subject-and-verb clause.

Because parallelle is the adjective form used before a noun.

• parallel = parallel
• parallelle parkering = parallel parking

In Afrikaans, adjectives used directly before nouns often take an -e ending. That is what is happening here.

So:

• parallelle modifies parkering
• moeilik does not take that ending here, because it comes after is

Because it is a predicate adjective, not an adjective directly before a noun.

Compare:

• parallelle parkering = adjective before a noun, so parallelle
• is moeilik = adjective after is, so just moeilik

This is very common in Afrikaans:

• Die boek is interessant.
• ’n Interessante boek

So the position of the adjective matters.

Because after tydens, Afrikaans normally uses a noun phrase, not a plain verb.

So:

• tydens parallelle parkering = during parallel parking

If you wanted to use a verb idea instead, you would need a different structure, for example:

• wanneer jy parallel parkeer = when you parallel park
• terwyl jy parallel parkeer = while you parallel park

In the given sentence, parkering is the noun parking.

No. There is no article needed here.

The sentence is talking about the activity in a general sense:

• during parallel parking

This is similar to English, where you would also usually not say during the parallel parking unless you meant one specific instance.

So tydens parallelle parkering is a general expression, and that is completely natural.

Because it follows the normal Afrikaans main-clause pattern:

subject + verb + complement

Here that is:

• Agteruitry tydens parallelle parkering = subject
• is = verb
• moeilik = complement/adjective

So the structure is very straightforward. Afrikaans often looks quite similar to English in simple present-tense statements like this.

Yes, that is also possible, and many learners find it easier to understand at first.

That version uses an infinitive construction:

• om ... te ry = to drive

So:

• Om agteruit te ry tydens parallelle parkering is moeilik. = To reverse during parallel parking is difficult.

The original sentence with agteruitry is a bit more compact and noun-like, but both are understandable.

A very natural alternative would be:

• Dit is moeilik om agteruit te ry tydens parallelle parkering.

This literally means:

• It is difficult to reverse during parallel parking.

Afrikaans often uses Dit is ... om ... te ... for statements like this, just as English often uses It is difficult to...

So the given sentence is correct, but this alternative may sound more conversational to some speakers.

A simple learner-friendly guide:

• agteruitry ≈ AKH-ter-ate-ree
• tydens ≈ TAY-dens
• parallelle ≈ pa-ra-LEL-uh
• parkering ≈ par-KEER-ing
• moeilik ≈ MOOY-lik

A few notes:

• g in Afrikaans is usually a harsh throat sound, not an English g
• ry does not sound exactly like English rye, but that is a rough approximation
• oei in moeilik is not pronounced like English spelling would suggest; it is closer to moo-y

Yes, when it is used as a normal verb phrase.

Compare:

• Ek ry agteruit. = I am reversing.
• Hy moet agteruit ry. = He must reverse.

But when it becomes the name of the activity, it is commonly written as one word:

• Agteruitry is moeilik.

So both forms exist, but they are used in different grammatical situations.

In this sentence, it simply means the activity of parallel parking.

So tydens parallelle parkering means:

• while doing parallel parking
• during the act of parking parallel to the curb

It does not have to mean a special technical maneuver; it can just refer to the general driving action.