Question

many a 什么意思？和many 什么区别

Answer 1

many a 与单数名词及动词连用, 表示"一个很大的数量"
Many a good man has been destroyed by drink. 许多好人都毁在了饮酒上.

many 与复数名词及动词连用, 表示大量.
<>We haven't got many books. 我们没有很多书.

Answer 2

many a后接单数名词，表示很多个，许多的，多的。如 I have been here many a time.我来过这多次。
many后接可数名词复数，相信这个不用做过多解释了吧。