how do you know

only a doctor can evaluate the semen to count the perm in it.

It depends on how high his sprem count is. Ejaculation does not mean fertile. He could ejaculate A LOT but not have many or any sperm.

amount ejaculation is not an indicator.

to find the fertility you have to find out how much live SPERM is in the ejaculate.

he'd have to go to a dr to get that done.

only way to tell is see a doctor and do a sperm count, i wouldnt want to a sperm count on the type of guy your talking about though, wouldnt even want him to be the father of my children. When i first met my husband he drank a lot and smoke ciggies a lot and we had 2 children very fast but he no longer drinks and cut and is trying to quit smoking

I have to agree with the other posters on this...I wouldn't want a child with a man that has these habits, either...he will not make a good father figure. I mean, think about it. Do you really think having a child with this person will make him grow up and change his ways? It won't. It doesn't work like that. Eventually he might wake up and smell reality but for right now, he's obviously stuck somewhere in la-la land. Let's say for example that you do have a child with this person, and he doesn't quit the weed and other bad habits...would you want your child to emulate what he's doing? Because children don't pick up the good habits, they pick the worst to copy. I didn't believe this until I had kids...and saw it happen. They look up to their parents and will copy (or try to) any behavior they think is cool or just because 'mom or dad does it.'
Good luck to you.