If you ask them a question, every single response is "what? or "what did you say man?"
If you are a stoner yourself, usually you can just tell. Sort of like a stoner 6th sense.
If they are funny and usually calm.
Sometimes you see them and their eyes are red as hell and others they aren't.
They are always "tired."
Check the bottom of their lighter. If it has black marks on the bottom of their lighter, you know they been using it to push down bowls / snub out joints.
Their lighter has no safety
If they smoke cigarettes, they hold it between their index and thumb, instead of between their middle find and index.
Their DVD collection includes half baked, how high, pineapple express, or any number of the other movies on this list.
They are always smiling.
They walk, move and/or talk slowly.
Half the cardboard has been ripped off their pack of papers
when a good friend says "you wanna come downtown and drink?" and all you can think about is a blunt or a bong.. and you don't wanna get stuck downtown with a bunch of dudes and no pot!
Forget half the things you went out to buy,come back with unecesary shopping.Forget what your talking about mid sentence(usually happens when around family or when people are actually listening to you).Like words.