I'm not sure but I think the following sentences are related to the certainty or uncertainty of the fact that he will come or not.Or I think would come indicates some kind of uncertainty than will come.so, If the speaker were certain he would use 'will'. for examples :
1.Do you think he'd come? | I'm sure he would. (Here the speaker isn't sure that he will come)shows uncertainty
- Do you think he will come? | I'm sure he will. (Here the speaker is sure that he will come ) shows certainity
Am i right here in my opinion?
If first sentence indicates uncertainity( if my openion is correct), But why there is the use of 'would' with 'sure' in first sentence?
context: is there the 'if clause' hidden in those sentences? What about if I already invited him(Tom) at my home and he haven't come yet to my home and i'm talking with one of my friend Ram about weather Tom will come or not.