Try to find out the most suitable task for him. Group members must understand each other's ability.

No one is happy to be given unwanted duties. I don't know whether this happens to you or not, sometimes other members in a team too concentrate on their work (or look down on the others) and seem to ignore one person who they think unimportant. This really dissapoints him a lot and then make him feel don't want to work. Don't give any member the feeling that he's not included in the team. And there's some people who don't believe in anyone's work and want to do all task alone -_- 

Believe me, this happened (at least to someone I know)

Make them take responsibility for their laziness, don't blame them when you don't know the reasons.

P/s: This's only my own opinion. If you don't agree, just ignore. :)

Indeed, We have the discussion. 

I seem that that person who work hard. Others would be getting to rely on him. But not me, Depend on my job now. It is easy to tell from whose work. Helping each other on a little things. Dont count it

Yeah,in my primary school when my friends and i worked in team my friends was lazy and i had to do everything alone.And on the end when professor complimented they was there to get compliment like all of us was working on project....totally unfair.

If you want to quick, you should go alone

If you want to far, you should go together

I hate TEAMWORK o_O! !  I am ending doing all the job alone. I prefer to work alone.