How Can You Tell If A Person Is A Pisces?

The simplest way is just to ask them:
'Let me guess, you're Pisces, right?'
For a while, that sort of question was
used as an 'ice-breaker'.  Nowadays it
sounds really lame (not a way to pick
up girls at all).  Last time some guy used
the line 'hey, baby, what's your sign?'
My answer was short, simple, and to
the point.
'Stop.'
Admittedly, it's been a long time since
that happened last, but I can assure you,
that would still be my answer, today.

Just ask them . Just as in any zodiac sign , and ask them some information about that zodiac. It wouldn't hurt. Even though it is an unusual question. You don't go to a person you have never met in your life , and ask them "Hey , What's your zodiac sign , dude?" LOL. Anyway , just ask , it won't be visible physically , if you probably know alot about a certain sign and loads of information and personalities of the zodiac sign , you would probably recognize them from their attitude and behaviour if you regard and observe them properly.

Easy.  They have scales and gills.

Check out their birth certificate.

D.O.B. :) i personally don't do star signs nor believe in them.

You find out their birthdate.

Ask them

You now how i said i want my friend over now she is

If there cold as a fish.  Trust me, I was married to one.

Well, they are adapted to certain things like water, strong willingness
adventurous, goodwilled