Ez a kerék nagyon nagy.

In Hungarian, when this directly modifies a noun, you normally use a demonstrative + article pattern:

• ez a kerék = this wheel
• az a ház = that house

So ez points to something nearby, and a is the definite article. Together they function like English this before a noun.

By itself, ez usually means this one or this thing.

• Ez nagy. = This is big.
• Ez a kerék nagy. = This wheel is big.

Hungarian often leaves out the verb to be in the present tense, third person.

So:

• Ez a kerék nagyon nagy. literally looks like This the wheel very big
• but it means This wheel is very big

This is completely normal in Hungarian.

Compare:

• A kerék nagy. = The wheel is big.
• Én fáradt vagyok. = I am tired.
• Te fáradt vagy. = You are tired.
• Ő fáradt. = He/She is tired.

Notice that in third person singular, the present tense is is usually omitted.

Kerék means wheel.

It is a singular noun here. In this sentence, it is the subject: the thing being described as very big.

Useful related forms:

• kerék = wheel
• kerekek = wheels

Depending on context, it can refer to a wheel on a vehicle, bicycle, cart, and so on.

Nagyon means very.

It intensifies an adjective or adverb:

• nagyon nagy = very big
• nagyon jó = very good
• nagyon gyorsan = very quickly

So in your sentence:

• nagy = big
• nagyon nagy = very big

Yes, they are related in form, but they do different jobs here.

• nagy = big
• nagyon = very

Historically they are related, but as a learner, the important thing is to treat nagyon as a separate common word meaning very.

So:

• nagy kerék = a big wheel
• nagyon nagy kerék = a very big wheel

No. Hungarian adjectives do not agree with nouns in gender, and Hungarian has no grammatical gender like he/she nouns or masculine/feminine adjective forms.

So nagy stays nagy regardless of the noun:

• nagy kerék = big wheel
• nagy ház = big house
• nagy asztal = big table

This is often easier for English speakers than languages with adjective agreement.

One thing to note: in predicate position, plural can affect the adjective:

• A kerék nagy. = The wheel is big.
• A kerekek nagyok. = The wheels are big.

So when the adjective is used like is big / are big, plural often shows up on the adjective.

A rough English-friendly guide is:

• Ez ≈ ez
• a ≈ short aw or uh
• kerék ≈ keh-rake with stress on the first syllable: KE-rék
• nagyon ≈ naw-dyohn or naw-yon, depending on how precisely you hear the gy
• nagy ≈ something like nawdy with a soft dy sound

A few pronunciation points:

• Hungarian stress is usually on the first syllable of each word.
• é is a long vowel, somewhat like ay in say, but purer.
• gy is a soft consonant sound that English does not have exactly. It is somewhat like the d in British-style duke or a soft dy sound.

So the sentence is roughly:

EZ a KE-rék NA-gyon NAGY

The basic sentence is perfectly natural as it is:

• Ez a kerék nagyon nagy.

Hungarian word order is flexible, but changes often affect focus or emphasis, not just style.

For a beginner, it is best to keep this normal order:

• Ez a kerék = topic / subject
• nagyon nagy = what you say about it

Other orders may be possible in context, but they can sound marked or emphasize a particular part. So unless you have a reason to stress something, use the sentence as given.

Because in Hungarian, when a demonstrative like ez or az comes before a noun, the noun normally also takes the definite article.

So:

• ez a kerék = this wheel
• az a kerék = that wheel

Saying Ez kerék would not be standard Hungarian.

This is one of the first patterns learners need to memorize.

Not exactly in the same way as English it.

Ez means this or this one/thing. It points to something close, physically or mentally.

Examples:

• Ez nagy. = This is big.
• Ez a kerék nagy. = This wheel is big.

For general it in a sentence, Hungarian often handles things differently from English and may simply leave the subject unspoken if context is clear.

So you should think of ez mainly as this, not as a direct equivalent of every English use of it.

It would become:

• Ezek a kerekek nagyon nagyok. = These wheels are very big.

Breaking that down:

• ezek a = these
• kerekek = wheels
• nagyon = very
• nagyok = big, plural predicate form

Notice two important plural changes:

1. The noun becomes plural:

   • kerék → kerekek

2. The adjective in predicate position also becomes plural:

   • nagy → nagyok

The difference is mainly in reference:

• A kerék nagyon nagy. = The wheel is very big.
• Ez a kerék nagyon nagy. = This wheel is very big.

With ez a, you are specifically pointing out this particular wheel, usually one near you or one already highlighted in the situation.

So ez a kerék is more specific and more demonstrative than just a kerék.