How do you say "probably''?
我们下个月肯定开始上课. 100%

我们下个月开始上课. 90%  as the base.

我们下个月很可能开始上课. 80%

我们下个月有可能开始上课. 70%

我们下个月可能开始上课. 50% as a middle base for not sure.

我们下个月好像不能开始上课. 40%

我们下个月不太可能开始上课. 30%

我们下个月不可能开始上课. 20%

我们下个月肯定不能开始上课. 0%

Sorry, the Chinese is really messy, isn't it? Those numbers are just for reference, please do not take it too much seriously.