when u meet arabian u dont know u say in general " alsalamu alikom " or " marhaba " . but if u know him/ her u can say " ahlan ,alsalamu alikom , keifek " . These at anytime of the day . But in the morning u say " sabah alkhair " and in the evening , afternoon or night u say " masaa al khair " . Generally in every time in all conditions u have to smile .

you can say "marhaba" "ahlan" "salamoalekom" good morning = sabah elkher good evening = masa' elkher

I remember - "salam" and "mahraba"

salam GG :) muslim arabic people say " salamo alaikom " = السلام عليكم , and arabic people generaly say " marhabane " = مرحبا ,

marhaba GG , hello = marhaba , assalamu alikoum