A gumiabroncs új és tiszta.

In Hungarian, the verb to be is usually left out in the present tense, third person.

So:

• A gumiabroncs új. = The tire is new.
• A gumiabroncs tiszta. = The tire is clean.

Hungarian does not need a separate word for is here.

But the verb does appear in other persons:

• Én új vagyok. = I am new.
• Te új vagy. = You are new.
• A gumiabroncs új. = The tire is new.

So this omission is completely normal.

A is the Hungarian definite article, meaning the.

• a is used before most consonant sounds
• az is used before vowel sounds

Examples:

• a gumiabroncs = the tire
• az autó = the car

So in A gumiabroncs új és tiszta, A simply means the.

Gumiabroncs is a noun meaning tire.

It is a compound word:

• gumi = rubber
• abroncs = tire / rim / hoop-type ring, depending on context

Together, gumiabroncs means tire in a more formal or technical way. In everyday speech, Hungarians also often say gumi when the meaning is clear.

In this sentence, új and tiszta are predicative adjectives: they come after the noun and describe it, like new and clean in The tire is new and clean.

Hungarian adjectives do not change for gender, because Hungarian has no grammatical gender.

In the singular, they also stay unchanged here:

• A gumiabroncs új.
• A gumiabroncs tiszta.

So unlike in many European languages, you do not need masculine/feminine or similar agreement.

A useful comparison:

• az új gumiabroncs = the new tire
  (attributive adjective, before the noun)
• A gumiabroncs új. = The tire is new.
  (predicative adjective, after the noun)

Yes. You can also say:

• A gumiabroncs tiszta és új.

Both are grammatical. The difference is mostly about focus, emphasis, or what sounds more natural in context.

English does something similar:

• new and clean
• clean and new

In many cases, either order works, but one may sound a bit more natural depending on what you want to emphasize.

A rough pronunciation guide is:

• A ≈ aw
• gumiabroncs ≈ goo-mee-aw-bronch
• új ≈ oo-y
• és ≈ aysh
• tiszta ≈ tees-taw

A few important spelling points:

• cs sounds like ch in church
• sz sounds like s in see
• plain s sounds like sh
• ú is a long u sound
• j usually sounds like English y

So:

• új is roughly oo-y
• tiszta begins with tisz-, where sz is a plain s sound

És means and.

So:

• új és tiszta = new and clean

It is the normal way to connect two words or phrases of the same type.

Examples:

• nagy és erős = big and strong
• gyors és olcsó = fast and cheap

Usually yes, in a sentence like this.

Tiszta commonly means:

• clean
• not dirty
• pure / clear, in some contexts

Here, with gumiabroncs, it clearly means clean.

So:

• A gumiabroncs tiszta. = The tire is clean.

It would be:

• A gumiabroncsok újak és tiszták. = The tires are new and clean.

Changes:

• gumiabroncs → gumiabroncsok
  plural noun: tires
• új → újak
• tiszta → tiszták

This is useful because in Hungarian, when adjectives are used like this after the noun, they often take plural marking too.

Not always. It depends on the meaning.

• A gumiabroncs új és tiszta. = The tire is new and clean.
• Egy gumiabroncs új és tiszta. = A tire is new and clean.
• Gumiabroncs új és tiszta. is generally not the normal choice for this meaning.

So if you mean a specific tire, A is correct.
If you mean an unspecified tire, use egy = a/an.

It is correct, but it sounds a bit more formal or technical than everyday speech.

In casual spoken Hungarian, people often say:

• gumi = tire / tyre, when the context is clear

For example:

• A gumi új. = The tire is new.

But gumiabroncs is a perfectly good standard word, especially in written, technical, or careful language.