Hava dün korkunçtu.

In Turkish, the verb to be is often built into the end of the predicate instead of appearing as a separate word.

Here, korkunçtu = korkunç + past tense form of to be.

• korkunç = terrible / awful
• -tu = was

So korkunçtu means was terrible.

-tu is the past-tense copula, meaning something like was.

The basic past copula is often shown as -di, but it changes form depending on vowel harmony and consonant assimilation:

• -dı
• -di
• -du
• -dü
• and after voiceless consonants: -tı, -ti, -tu, -tü

Since korkunç ends in ç, which is voiceless, d changes to t.
Also, the last vowel in korkunç is u, so the suffix becomes -tu.

That is why it is korkunçtu, not korkunçdu or korkunçti.

Hava can mean both air and weather, depending on context.

In this sentence, it means weather:

• Hava dün korkunçtu. = The weather was terrible yesterday.

If the context were different, hava could also mean air, atmosphere, or even mood in some expressions.

Turkish does not have definite articles like the in English.

So hava can mean:

• weather
• the weather

The context tells you which one is meant. In this sentence, English naturally uses the weather, but Turkish simply says hava.

Turkish word order is flexible, but the most neutral order is often subject + time + predicate or time + subject + predicate.

So these are all possible:

• Hava dün korkunçtu.
• Dün hava korkunçtu.

Both mean the same thing: The weather was terrible yesterday.

The version with dün in the middle is perfectly normal.
Turkish often places time expressions before the final predicate.

Yes, absolutely.
Dün hava korkunçtu is very natural and may even sound slightly more common in everyday speech.

Compare:

• Hava dün korkunçtu.
• Dün hava korkunçtu.

Both are correct. The difference is mainly one of emphasis and information flow, not basic meaning.

Korkunç is an adjective meaning terrible, awful, or sometimes frightening, depending on context.

In this sentence, it functions as the predicate:

• hava = subject
• korkunçtu = was terrible

So although korkunç is an adjective, it behaves like the main descriptive part of the sentence.

Not always. It can be quite strong, but in everyday Turkish it is often used the way English speakers use terrible or awful.

So in a sentence about weather, korkunçtu usually means:

• it was awful
• it was terrible

It does not necessarily mean something literally horrifying.

Turkish often does not use dummy subjects like English it in sentences about weather, time, or general conditions.

English says:

• It was terrible yesterday.

Turkish instead says:

• Hava dün korkunçtu.

So Turkish uses the noun hava directly, without needing an extra it.

The present version would usually be:

• Hava korkunç. = The weather is terrible.

In third-person present tense, Turkish often has no visible word for is.
So:

• korkunç = terrible
• korkunçtu = was terrible

This is a very common pattern in Turkish.

You would use değil in the past form:

• Hava dün korkunç değildi. = The weather wasn’t terrible yesterday.

Breakdown:

• korkunç = terrible
• değildi = was not

So Turkish does not usually negate this kind of sentence by changing korkunçtu directly. Instead, it uses değil.

It is pronounced roughly like kor-kunch-tu.

A few points:

• ç sounds like ch in church
• the final tu is clearly pronounced
• stress in Turkish often falls near the end, though natural sentence rhythm matters too

So the word is approximately:

• kor-kunç-tu

More or less:

• Hava = weather
• dün = yesterday
• korkunçtu = was terrible

So a very literal translation is:

• Weather yesterday was terrible.

But natural English is:

• The weather was terrible yesterday.

That is a good example of how Turkish and English use slightly different sentence structure while expressing the same idea.