Possessive Constructions

Formation of Possessive Constructions
The basis of a Possessive Construction is a noun such as iç - inside, interior.
With this we can form a Possessive Construction like - evin içi - the inside of the house.

The first noun is the possessor with a Genitive Suffix (Suffix of Ownership) - ev-in - of the house, the house's.
Whilst the second noun is the possessed object and thus is given the Object Suffix - iç i - the (its) inside.

Extended Forms

If the motion toward, static or motion away suffix is the added we have:
evin içine - into the house [to the inside of the house]
evin içinde - in the house [at the inside of the house]
evin içinden - from within the house [from the inside of the house]

Consider the following examples
Odanın içinde yer bulup oturdu. - He found a place in the room and sat down.
Bu kutuda ne var? - What is in this box?
Bilmem, içine bakmadım. - I don't know,I have not looked inside.
Bankanın içinden bir ses geliyordu. - A sound was coming from inside the bank.
Bu odanın içindekiler birbirine sohbet ediyor. - The people in this room are chatting to each other.

Omission of the Possessive Suffix
In many cases the suffix of Possession may be omitted from the first noun with very little difference in meaning:
Fabrikanın içinde çok insan çalışıyor. - Fabrika içinde çok insan çalışıyor.
- Both the above mean - Many people are working in the factory.
But in other cases there is a distinction in definiteness and specific meaning when the Possession Suffix is omitted from the first noun.

Definite Possession

Frequently the distinction is one of definiteness (or specificity). If the first noun carries the Possessive Suffix, it is definite (specific) and refers to a particular specific object known to the speaker.
Bu hayvanlar mağaranın içinde yaşar - These animals live inside the cave. [a definite cave]
Eşyalarımı kutunun içine koydum - I put my things into the box [A definite box]

Indefinite Possession

If however the Possessive Suffix is absent then the noun becomes indefinite and is often used in a general sense:
Bu hayvanlar mağara içinde yaşar - These animals live inside caves. [caves generally]
Eşyalarımı kutu içine koydum. - I put my things into a box/boxes [Indefinite box/boxes]

Idiomatic Forms of Possession

Sometimes the Possessive Compound corresponds to an idiomatic expression:
Ali'nin dairesi, şehrin içinde - Ali's office is (right) in the town
Ali'nin dairesi, şehir içinde - Ali's office is in town ("downtown" - USA usage)

Metaphorical Sense

Also the Possessive (genitive) is normally omitted when it is used in a metaphorical instead of actual physical sense:
Bir hafta içinde kitabını bitirecek. - He will finish his book within a week.
İki gün içinde geri döneceğim. - I'll return inside two days.

Demonstratives are Definite

However, when the first noun is already definite (as in the case of the Demonstrative Pronouns - this and that) then it must have a Possessor Suffix:
Bu şehrin içinde çok insan var. - There are many people (living) in this city.
Bu bahçenin içinde çok çeşit çiçek bulunur. - Many type of flowers are to be found in this garden.
Yangın, o adamın ofisin içinde başlamış. - Apparently [-mış] the fire started in that man's office.
O hayvanlar su mağaranın içinde yaşar - Those animals live inside that cave.