a dining room, a hall and 'three rooms' (to znaczy jakie? - tutaj chyba masz na mysli bedrooms - ale bedroom to wczesniej juz napisales?-cos tu nie tak).
One room is 'me' (nie ty nie jestes 'a room' room jest DLA ciebie FOR ME).
'In' ON the 'schelf' (ortog) of THE desk there's my mobile phone and AN mp3 player.
'There' THEY are on THE 'schelf' (ortog) of THE bed.
The 'wordrobe' (ortog) is near the armchair. 'In' ON THE first shelf 'there' (niepotrz) are my school books. 'In' ON THE second shelf 'there' (niepotr) are my clothes. 'In' ('In' to generalne znaczy 'w' a tutaj mowisz 'na' ON) the third shelf there are dictionaries. THE chair IS usually 'there's' (niepotr) near the desk.