We use can to talk about future actions which we will be able to do because of present ability, present circumstances, present decisions etc.
• She can win the race tomorrow if she tries really hard.
In other cases we prefer other structures, for example will be able to.
• I'll be able to speak French at the end of this course. (NOT I can speak French ...)
Practical English Usage, Swan, p. 99.
I don't understand how the first sentence is different than the second one! I simply don't get the point. Should the second sentence be more specific, so we can use can in it? Something like,
If I keep taking French classes like I am now, I can speak French at the end of the course.