when I thought this sweet innocent girl was cute then she spoke and boy did she have a mouth on her!
That might have been me you saw.

In all seriousness, it is like trying to judge a person for any other personality trait. I would tell you that yes, you can tell, but just like judging someone for any other reason, you can also be wrong. I like to think I can hunt out a male submissive from ten miles away, and a lot of the time I can, but I have been wrong. Sometimes a person is dominant or submissive but only in a particular situation, and if that's how you first see them then you're not getting the whole picture. Also sometimes people don't know who they are, or even more confusing, can change who they are.

But if it's guidelines you want,
how can a Dom/me tell who is a submissive,
Most of them tend to say "okay" a lot and if someone else tells them (or a group they are part of) what to do, they're relieved, as in "phew, someone's in charge." They tend to do what I tell them, but I can't go by that alone since 90% of people I meet tend to do what I tell them. Unless there's another dom in the room, I am in charge.

can You tell on the street by looking at someone ?
No. You can't judge a person's personality by what they look like alone.

can You tell from a short converstation.
Depends on the conversation. But frequently, you can make a good guess after talking for a few minutes. But it's just a guess.

i always read about people who didn't know until they met someone in a club who was an experienced Dom and made them realise who they truely are.
Do people change parts of who they are and discover things about themselves when they're in a serious relationship? Of course.