A stég oldala nedves.

A is the Hungarian definite article, meaning the.

Before consonant sounds, Hungarian uses a. Before vowel sounds, it uses az.

So:

• a stég = the pier/dock/jetty
• az asztal = the table

Because oldala contains a possessive ending.

• oldal = side
• oldala = its side / his side / her side / the side of it

In Hungarian, when you talk about a part of something, you very often use a possessive form where English would simply say the:

• a ház teteje = the roof of the house
• az autó ajtaja = the car’s door
• a stég oldala = the side of the pier

So oldala is the natural Hungarian way to say the side when it belongs to the pier.

It is a possessor + possessed noun structure.

• a stég = the pier
• oldala = its side

Together, a stég oldala literally works like the pier its side, but in natural English this becomes the side of the pier or the pier’s side.

This is a very common Hungarian pattern.

It could be, but Hungarian often leaves off -nak/-nek in simple possessive phrases.

So both are possible:

• a stég oldala
• a stégnek az oldala

The version without -nek is very common and neutral.
The version with -nek can sound a bit more explicit, marked, or emphatic depending on context.

For learners, it is useful to recognize that both can mean the same thing.

Because in Hungarian, the verb to be is usually left out in the present tense, third person singular and plural when the predicate is a noun, adjective, or similar expression.

So:

• A stég oldala nedves. = The side of the pier is wet.
• A ház nagy. = The house is big.
• A fiú fáradt. = The boy is tired.

But in other persons, Hungarian does use forms of van:

• Fáradt vagyok. = I am tired.
• Fáradt vagy. = You are tired.

Nedves is an adjective, meaning something like wet, damp, or moist, depending on context.

In this sentence it is used predicatively, meaning it describes the subject:

• A stég oldala = the subject
• nedves = what is being said about it

So the structure is basically:

[subject] + [adjective]

No. Hungarian adjectives do not agree the way adjectives do in many Indo-European languages.

Hungarian has no grammatical gender, and the adjective usually stays the same form:

• nedves oldal = wet side
• nedves oldalak = wet sides
• Az oldal nedves. = The side is wet.
• Az oldalak nedvesek. = The sides are wet.

Notice that in predicate position, the plural may appear on the adjective (nedvesek) when the subject is plural, but there is still no gender agreement.

Yes. That is also a correct Hungarian sentence.

Hungarian word order is flexible, and changing the order often changes the focus or emphasis.

• A stég oldala nedves. = neutral statement
• Nedves a stég oldala. = emphasis on wet

So if the important new information is that the side is wet, putting nedves first is very natural.

Both can relate to wetness, but they are not always identical.

• nedves often means damp, moist, or wet to the touch
• vizes often suggests watery, covered with water, or soaked/wet with water

In many contexts they can overlap, but nedves can sound a bit milder or more general.

So:

• A stég oldala nedves. = the side is damp/wet
• A stég oldala vizes. = the side is wet, watery, or covered in water

The exact difference depends on context.

Stég is pronounced roughly like shtayg, with a long é sound.

A few pronunciation notes:

• s in Hungarian sounds like English sh
• t is a clear t
• é is a long vowel, roughly like the vowel in say, but steadier
• g is a hard g

So stég sounds approximately like shtehg/sh-tayg, depending on how narrowly you approximate it in English.

In this kind of possessive construction, Hungarian normally places the article before the whole noun phrase, not separately before the possessed noun.

So:

• a stég oldala = the side of the pier

You do not normally say a stég a oldala.

If you use the fuller possessive pattern, then you can get:

• a stégnek az oldala

Here az oldala is part of that expanded structure. But in the shorter, very common version, one article at the front is enough.

Grammatically, oldala is a third-person possessed form, so literally it means his side / her side / its side.

But in sentences like this, Hungarian uses that form simply because the side belongs to something already named:

• a stég oldala = the side of the pier

So even though the form is technically possessive, in natural English you usually translate it as the side, not its side, unless you want extra emphasis.