Teklif dosyası teknik şartnameyi içeriyor.

This is a very common Turkish noun-compound pattern.

In teklif dosyası, both words are nouns:

• teklif = proposal / offer / bid
• dosya = file / dossier

When one noun describes another in Turkish, the second noun usually takes the 3rd person possessive-type suffix:

• teklif dosyası = proposal file / bid file

So the pattern is:

• Noun + Noun-(s)I

Examples:

• öğrenci kartı = student card
• şehir merkezi = city center
• proje dosyası = project file

So teklif dosyası is the normal way to say proposal file.

Not in the usual ownership sense.

The ending -sı is the same form you also see in possessives, but in a noun compound like teklif dosyası, it does not necessarily mean actual possession.

So:

• teklif dosyası does not mean something like the file belonging to the proposal
• it simply means proposal file

This is one of the important things English speakers have to get used to: Turkish often uses a possessive-looking ending to build compound nouns.

Because dosya ends in a vowel.

The compound suffix here is basically -(s)I. The s appears when needed between two vowels.

• dosya
  • -(s)ı → dosyası

Compare:

• kart
  • -ı → kartı
• dosya
  • -sı → dosyası

That s is a buffer consonant that makes pronunciation smoother.

Because it is the definite/specific direct object of the verb.

The verb içermek means to contain/include. What is being included? teknik şartname. Since it is a specific technical specification, Turkish marks it with the accusative ending.

So:

• teknik şartname = technical specification
• teknik şartnameyi = the technical specification, as a specific direct object

This is very similar to how Turkish often marks a definite object.

Because şartname ends in a vowel, and the accusative suffix also begins with a vowel.

The accusative suffix is basically:

• -ı / -i / -u / -ü

But after a vowel, Turkish inserts a buffer y:

• şartname
  • -i → şartnameyi

Other examples:

• masa
  • -yı → masayı
• kapı
  • -yı → kapıyı
• projeyi from proje

So the y is just a linking consonant.

Because of vowel harmony.

The accusative has four possible forms:

• -ı
• -i
• -u
• -ü

The choice depends on the last vowel of the noun. In şartname, the last vowel is e, so the correct accusative vowel is i:

• şartname → şartnameyi

So this is both:

• accusative marking
• vowel harmony
• plus buffer y because the noun ends in a vowel

In this sentence:

• Teklif dosyası = subject
• teknik şartnameyi = object
• içeriyor = verb

A big clue is the accusative ending on şartnameyi. That tells you it is the direct object.

The subject, teklif dosyası, has no special ending here; it is in the basic nominative form.

So the structure is:

• Subject + Object + Verb

which is the normal Turkish order.

İçermek is the dictionary form, meaning to contain / include.

In the sentence, you need a conjugated verb, so içermek changes to içeriyor:

• içermek = to contain
• içeriyor = it contains / is containing

This is the present continuous form, but in Turkish it is often used where English would simply use the present tense.

So içeriyor can naturally mean:

• contains
• is containing

depending on context.

İçerir is the aorist/simple present and can also mean contains, but içeriyor is very common in everyday and business Turkish.

That is the default order, yes:

• Teklif dosyası teknik şartnameyi içeriyor.

But Turkish word order is flexible, and changing it can change emphasis.

For example:

• Teknik şartnameyi teklif dosyası içeriyor.

This could put more focus on teknik şartnameyi.

Still, for learners, the safest default is:

• Subject + Object + Verb

And in this sentence, that default order sounds perfectly natural.

You might hear forms without the accusative in some contexts, but here -yi is the natural choice because the object is specific.

Compare the idea:

• teknik şartnameyi = the technical specification, a specific one
• teknik şartname = technical specification, less specifically marked

In formal/document language, if you mean a particular technical specification, the accusative is the expected form.

So for this sentence, teknik şartnameyi içeriyor is the best version.

Turkish does not have articles like English the and a/an in the same way.

Instead, Turkish often shows definiteness or specificity through:

• context
• word order
• case endings, especially the accusative

So in this sentence, the specificity of teknik şartnameyi is shown by the accusative ending, not by a separate word like the.

That is why Turkish can express something like the technical specification without using an article.

Yes, it sounds fairly formal or administrative because of the vocabulary:

• teklif dosyası = proposal/bid file
• teknik şartname = technical specification

These are common in business, procurement, engineering, and official documents.

The verb içeriyor itself is neutral and normal. In even more formal written Turkish, you might also see:

• Teklif dosyası teknik şartnameyi içermektedir.

That sounds more official and written, but içeriyor is completely correct and natural.