tolong buatkan dialog meminta dan memberi kepastian

N:i m not a good mood because i've yellow teeth .i think will dentist to whiten teeth
F:no don't do that ,try my hints,first ,use the charcoal , puree charcoal be powder and rub on teeth
n: are you certain?
f:definetelly i 've already tried this to sevesal times and it works for me