YOU SAID:
I haven't seen my best friend in a while
INTO JAPANESE
私はしばらくの間私の親友に会っていません
BACK INTO ENGLISH
I haven't seen my best friend for a while
INTO JAPANESE
私はしばらくの間私の親友に会っていません
BACK INTO ENGLISH
I haven't seen my best friend for a while
Well done, yes, well done!