Bu bina çok çirkin.

In Turkish, the verb to be is often not stated in simple present-tense sentences like this when the subject is he/she/it or a noun.

So:

• Bu bina çok çirkin. = This building is very ugly.

This is called a nominal sentence. Turkish often leaves the present-tense is unspoken.

You may sometimes see:

• Bu bina çok çirkindir.

The -dir adds a more formal, definite, or explanatory tone, but in normal everyday speech it is usually omitted.

Bu means this.

So in this sentence:

• bu bina = this building

A helpful comparison:

• bu = this
• şu = often this/that (something being pointed out, a bit less close or newly brought to attention)
• o = that

So Bu bina is the normal way to say this building.

In Turkish, demonstratives like bu usually come before the noun, just like in English.

• bu bina = this building
• bu ev = this house
• bu araba = this car

So the order is:

• bu
  • noun

Because çirkin is the predicate adjective here: it describes the subject bu bina.

The structure is:

• Bu bina = subject
• çok çirkin = description of the subject

So Turkish is doing something like:

• This building very ugly.

with the present-tense is understood.

Compare these two:

• çirkin bina = ugly building
  
  • here çirkin directly modifies bina
• Bu bina çirkin. = This building is ugly.
  
  • here çirkin is the predicate, so it comes later

Because çok means very, and in Turkish, words like very normally come before the adjective they modify.

• çok güzel = very beautiful
• çok büyük = very big
• çok çirkin = very ugly

So:

• Bu bina çok çirkin. = This building is very ugly.

Yes. Çok is a very common word and can mean different things depending on context:

• çok güzel = very beautiful
• çok bina = many buildings
• çok çalışıyor = works a lot

In your sentence, because çok is before an adjective (çirkin), it means very.

A simple English-friendly guide:

• Bu ≈ boo
• bina ≈ bee-NAH
• çok ≈ chok
• çirkin ≈ CHEER-kin, but with a short, less English-like first vowel

A few important letters:

• ç = ch as in chair
• ı = a vowel that does not exist in English; it is not ee. It is a more relaxed, central vowel. In çirkin, the first vowel is i, but learners often also want to know that Turkish has both i and ı, and they are different letters.

More careful breakdown:

• çirkin = chir-kin, with i as in sit or slightly closer to ee depending on accent, but definitely not eye

No. Turkish adjectives do not agree with nouns in gender or number.

That means çirkin stays the same:

• çirkin bina = ugly building
• çirkin binalar = ugly buildings

And in full sentences:

• Bu bina çok çirkin. = This building is very ugly.
• Bu binalar çok çirkin. = These buildings are very ugly.

No masculine/feminine change, and no plural change on the adjective.

Because it is the subject of the sentence, and subjects in Turkish usually appear in the basic dictionary form, with no case ending.

So:

• bina = building
• bu bina = this building

If it had a different role in the sentence, it might take an ending:

• bu binayı = this building (object)
• bu binada = in this building
• bu binadan = from this building

But in Bu bina çok çirkin, it is just the subject, so no ending is needed.

Yes, but it changes the emphasis.

• Bu bina çok çirkin. = neutral, standard order
• Çok çirkin bu bina. = more emphatic, like This building is really ugly
• Bu bina çirkin. = less strong because çok is removed

Turkish word order is flexible, but the neutral teaching pattern is best to learn first:

• Subject + description

So for beginners, Bu bina çok çirkin. is the best basic form.

You use değil for negation in this kind of sentence.

• Bu bina çok çirkin değil. = This building is not very ugly.

If you want This building is not ugly, then:

• Bu bina çirkin değil.

So in these adjective sentences, the negative usually comes with değil, not by changing the adjective itself.

You add the question particle mi (which changes form by vowel harmony: mı, mi, mu, mü).

Here the natural question is:

• Bu bina çok çirkin mi? = Is this building very ugly?

Important points:

• mi is written separately
• it usually comes after the word or phrase being questioned

Examples:

• Bu bina çirkin mi? = Is this building ugly?
• Bu bina çok mu çirkin? = Is this building very ugly? / Is it very ugly?
  (focus on çok)

They are different structures:

1. Bu bina çok çirkin.
   = a full sentence
   = This building is very ugly.

2. Bu çok çirkin bina
   = a noun phrase, not a complete sentence by itself
   = this very ugly building

So:

• çok çirkin before bina = directly modifies the noun
• çok çirkin after bu bina = describes the subject in a full sentence

Yes. This is a very useful basic pattern:

• Bu ev çok güzel. = This house is very beautiful.
• Bu oda çok küçük. = This room is very small.
• Bu araba çok pahalı. = This car is very expensive.
• Bu kitap çok ilginç. = This book is very interesting.

So the pattern is:

• Bu + noun + çok + adjective

It is one of the most common sentence patterns in Turkish.