Whenever we see two related nouns, the second one must be either in the accusative or the genitive. 

It is important to know which one, because the meaning changes.

ένα ποτήρι νερό  – a glass of water (content) (accusative)

ένα ποτήρι νερού – a water glass (made for this) (genitive)

In this lesson we will explore the noun + noun in genitive

The genitive case has lots of functions. For the purpose of this lesson, we will summarize them as follows:

– ownership

– characteristics

Examples

Τα κλειδιά του αυτοκινήτου – the car keys

Τα ρούχα της δουλειάς – the work clothes

Το πρόγραμμα της τηλεόρασης – the tv program

Τα γυαλιά ηλίου – the sunglasses 

Η πόρτα του σπιτιού – the house door

Τα παπούτσια του χορού – the dance shoes 

Ο χώρος εργασίας – the work space

Note:

The “important” noun is mentioned first. 

We don’t say “a car key” but “a key of/for car”.