The only way to know is to know what the parent plants are, if growing from unknown seed then it is a toss up. You can’t really tell this early on, and will never have any certainty without knowing where the seed came from and knowing its genetic lineage.
Also a plant with mixed heritage can often show fat broad indica/kush like leaves and then later after it grows bigger it can start growing more like a haze/sativa and even develop numerous skinny leaves from then on like a haze sativa.
I can attest to that. I’ve got 3 strains growing right now. A pineapple express (haze), an OG Kush, and White widow.
They all looked very similar at the beginning but after a while 4 of the hazes have wide leaves, 2 have narrow leaves but the tall and lanky build. All of the kushes stayed small and bushy, but one set of leaves went wide, the rest narrow. The widows all have tiny leaves compared to the others, but 2 of them are wide, and 2 of them are narrow.
My point is, a lot of times you won’t know until you smoke them, and sometimes it’s even hard to tell at that point.
Everything we plant into a pot has a little flat popsicle stick with the name of the strain.
Thank you for the info