very much 和 very many 的 区别

very much 和 very many 的 区别
我是英语的初学者哈.他们区别不太清楚.是这样的2句对话
What about pencils?那么铅笔呢?
I can't buy very many.我不能买很多枝.
What about coffee?那么咖啡呢?
I can't buy very much.我不能买许多.
区别 是在 很多枝 和许多么?
能帮我解释下么