A kötény tiszta.

In Hungarian, a and az are the definite articles, so they mean the.

• a kötény = the apron
• egy kötény = an apron / one apron

Hungarian uses:

• a before most consonant sounds
• az before vowel sounds

So:

• a kötény
• az alma = the apple

In Hungarian, the verb to be is often left out in the present tense when talking about something in the third person.

So:

• A kötény tiszta. = The apron is clean.

There is no need to say a separate word for is here.

Compare:

• Én tiszta vagyok. = I am clean.
• Te tiszta vagy. = You are clean.
• A kötény tiszta. = The apron is clean.
  (not usually A kötény tiszta van — that would be wrong)

Here, tiszta is an adjective, meaning clean.

In this sentence it works as a predicate adjective, meaning it describes the subject:

• A kötény = the subject
• tiszta = describes the subject

So the structure is basically:

• The apron
  • clean
• understood as The apron is clean

No. Hungarian adjectives do not usually agree with the noun in number or gender the way they do in some other languages.

So:

• a tiszta kötény = the clean apron
• a kötény tiszta = the apron is clean

The adjective tiszta stays the same.

Also, Hungarian has no grammatical gender, so there is no masculine/feminine/neuter adjective agreement to worry about.

This is a very common and important question.

• A tiszta kötény = the clean apron
  Here, tiszta comes before the noun, so it directly modifies the noun.

• A kötény tiszta = The apron is clean
  Here, tiszta comes after the noun and functions as the predicate.

So word position changes the structure:

• adjective + noun = a noun phrase
• noun + adjective = a full statement

A helpful rough pronunciation is:

kötény ≈ KUH-tayny or KER-tayny
but with Hungarian sounds that do not match English exactly.

A few details:

• ö is a rounded front vowel, somewhat like the vowel in German schön or French peu
• é is a long ay-like sound
• ny is like the ny in canyon

So kötény sounds roughly like kö-tény, with stress on the first syllable.

A rough pronunciation is:

tiszta ≈ TEES-taw or TIS-taw

More exactly:

• ti has an ee-like vowel
• sz in Hungarian is pronounced like English s
• a is a short open vowel, somewhat like o in British hot or a in father, depending on accent

Important spelling note:

• Hungarian sz = English s
• Hungarian s = English sh

So tiszta begins with a plain s sound in the middle, not sh.

Hungarian stress is very regular: it almost always falls on the first syllable of the word.

So:

• KÖtény
• TISZta

This makes pronunciation easier than in English, where stress is less predictable.

The accent marks are part of the spelling and usually show a different vowel quality and/or vowel length.

In this sentence:

• ö is a different vowel from o
• é is a long vowel, different from e

So you should not ignore the accents. They are not optional.

For example:

• e and é are different vowels
• o, ó, ö, and ő are all distinct in Hungarian

Yes, but the basic sentence A kötény tiszta. is the most neutral way to say The apron is clean.

Hungarian word order is flexible, but changes often add focus or emphasis.

For example, changing word order can highlight a particular part of the sentence. In simple beginner sentences, though, it is best to learn:

• A kötény tiszta.

as the normal, neutral pattern.

It is singular: the apron.

If it were plural, it would be:

• A kötények tiszták. = The aprons are clean.

Notice that in the plural:

• kötény → kötények
• tiszta → tiszták

When the adjective is used predicatively with a plural subject, it commonly appears in the plural form too.

No, not here.

Hungarian often leaves out subject pronouns when they are unnecessary, and in this sentence the noun A kötény already tells you what the subject is.

So Hungarian says:

• A kötény tiszta.

not something like:

• A kötény az tiszta
  unless you are adding special emphasis in a particular context.

Possibly, depending on context. Tiszta most commonly means clean, but like many adjectives, it can have related meanings such as pure, clear, or neat/spotless in the right situation.

In this sentence, with kötény (apron), the most natural meaning is simply:

• The apron is clean.