A preposition is a little word that is put before a noun to describe its position and many other things. For example: on a table, behind a table, from a table, etc.

English is known for having a lot of prepositions and an elaborated system of their use. In fact, what is being said in English using prepositions is said in Lithuanian by way of cases.

We will not be able to do without cases, however! In Lithuanian, when a preposition is put before a noun, the noun is required to be in a particular case. The case, depending on the preposition, can be either genitive, dative, accusative or instrumental.

Your first preposition is going to be ant, which means on. This preposition changes its nouns into the genitive case:

on a table: ant stalo

Do you remember that a table is stalas?

Knyga yra ant stalo. A book is on the table.
Dvi knygos yra ant stalo. Two books are on the table.
Ant stalo yra dvi knygos ir pieštukas. Two books and a pencil are on the table.
Ar mano pieštukas yra ant knygos? Is my pencil on the book?
Kodėl tavo knyga ne ant stalo? Why isn't your book on the table?