YOU SAID:
I like a boy in the class next to mine
INTO JAPANESE
私は私の隣のクラスの男の子が好きです
BACK INTO ENGLISH
I like the class boy next to me
INTO JAPANESE
私は隣のクラスの男の子が好きです
BACK INTO ENGLISH
I like the boys in the next class
INTO JAPANESE
私は次のクラスの男の子が好きです
BACK INTO ENGLISH
I like the next class of boys
INTO JAPANESE
私は次のクラスの男の子が好きです
BACK INTO ENGLISH
I like the next class of boys
That didn't even make that much sense in English.