Friend with stutter

[douglas]

I'm a student, one of my friends in university has a stutter, also, he has moved away from home (on his own) to another country to study

he says back home he had more or less been able to 'get over' the stutter. however, he has often complained that it has come back since he has started university

he has settled in a bit more since we first started and some days his stutter is unnoticeable when we are just talking casually in groups of friends

however, in certain situations, particularly when we deliver group presentations, the stutter comes back. thankfully the lecturer is quite understanding, but sometimes he has been a little dismissive about meeting time conditions

i've read a few pages on the net which seem to dismiss the idea that being nervous causes stuttering (and that suggesting such a thing could be offensive) but with my friend it seems to be the primary cause, and he has agreed when I’ve bought it up in conversation

my question is, as a friend how can i be helpful and not offensive?

thanks