You got several options.
- People who are open enough can see their soul is different. That's the most accurate but not possible for most of us.
- They do have specific physical features (many different features actually) and having kike features gives them up as at least partially kike. That's the easiest for people not open enough but sometimes they are race mixied or got chirurgy and it's trickier. See the jos guides on kike physical features.
- Sometimes you just have the feeling sometimes isn't right and they may be jewish. Depends on your perception again but you definitly don't need to be able to see a soul to "feel" things aren't right.
- But for what you ask (actual traits) well it's harder to determine that way because they are very good at lying and deceiving people. So they may appear nice to backstab you better. Or they may appear dull and ordinary while they are a monster inside.
Generally they have shitty health, a lot of money (they hide it when in gentile lands) and they only care about themselves. Popping reptilian eyes and complete lack of empathy are huge giveaways BUT they are good at faking human emotions.
They are huge in the media, law, medicine and of course finance and banking. Be more careful when somebody is from these areas.
Oh and kikes are pro kike and pro pissrael obviously. That's actually a very clear hint.
If somebody tries to blame the problems of the world on another group or is part of the alt right while ignoring the jewish problem that's a red flag. They are either a shabbos goy or a kike. In all cases an enemy.
Also promoting race mixing and all forms of degeneracy in general. And promoting any form of alt right movement destined to fail or that never talks or hints at ZOG or straight up promoting christianity as a solution for whites like (((Nathanael))).
But sometimes they will try to bullshit you by saying they are against Israel. The "ultra orthodox" types try do this to confuse people and present the kikes as not unite. But they remain lying kikes.
Other hints : curly hair, curly beard, full uncut beard for men (the "rabbi" look)
Hats for men (can be other hat then kippah) only for "religious" kikes however.
That's all I had in mind.