Duduk = Sit. For example: - Saya duduk di kursi (I sit on a chair) Duduk - duduk = It can be one person, or more than one person. This word is often used to explain an activity of doing nothing, just sit and talk or like "chilling somewhere" For example: - Saya duduk - duduk saja di cafe. (I just sit at the cafe) Cerita - cerita = A word that is spoken with the intention that you can tell a story to him/her. But, Cerita - cerita, could be used as a plural of "cerita" (story). For example: - Bagaimana perjalananmu di Jepang? Cerita - cerita dong! (How was your trip in Japan? Tell me!)

"Duduk" is that mean : just seat down , but "duduk" that mean: you gather with people somewhere and relax together while sharing stories. "Cerita" is that mean: some story ,but "cerita-cerita" that means: you gather with people somewhere and share stories with each other.

Both mean the literal meaning but they emphasize the interaction among the doers. "Mereka duduk-duduk di sana" means "they are sitting/ sit there" but the action isn't just sitting upright and do nothing else, they may be chatting, eating, drinking, etc. while sitting.

..