'Man weiß ja nie, aber...', "You never know, but..." => In this case, "ja" is more or less working as a filler word. It underlines that the speaker is saying something important/intimate. It's often used in sarcastic/ironical remarks, as a self-affirmation, slendering or to express that something is (actually) commonly known (even if it's not). Popular examples: "Ich habe es dir ja gesagt!" => Meaning: Look, I was so right! "Du weißt ja, dass ich letzte Woche Martin getroffen habe. Heute erfahre ich, dass er nächste Woche heiratet. Warum hat er mir das nicht selbst gesagt?" => In this case, "Du weißt ja" means "You know because I told you". "Man weiß ja nie, aber..." => "Man weiß ja nie" is usually used to express an adverse conduct towards the person one is talking about. Neighbours, colleges and so on.

Hello Dear! My names are Sarah ayman from Syria. How are you doing? I came across your profile today and became interested to know you more better. Please I will like you to contact me on my privet email address here ( [email protected] )so that I can give you my photo and tell you more about myself. Thanks.