Difference between "a great many" and "many a great"

Dear Torsten,
I am confused with two words " a great many" and " many a great". I would be thankful if you could take the trouble to clear my confusion. I will be eagerly waiting for your reply letter. Thanks, partha

Hello Partha,

The difference lies in what the word ‘great’ refers to.

A great many:
“A great many people think the same” = Large numbers of people have thought that.
‘Great’ refers to ‘many’, and emphasises the high number. Not just many but a large number of many.

“Many a great man has thought the same.” = Large numbers of great men have thought that.
‘Great’ refers to ‘men’ and emphasises their importance. Not just men but successful men.

Thank you. I have got it. Now, pl. let me know about the uses of ’ a lot of". How can I use this phrase at the beginning of a sentence or in the middle of a sentence? I’ll be eagerly waiting for the answer. Thanks. Partha.

I could have used ‘a lot of’ in my first reply to you! Instead of ‘large numbers of men…’ I could have said, ‘A lot of men…’
“A lot of people I know are going on the outing.”
“There are a lot of dogs in the park today.”

‘A lot of’ means a ‘large number of’.

‘A lot of’ is a little more specific than ‘lots of’ in that it refers to one particular group - in my examples, people known to me (rather than people) and dogs (rather than just animals).
“Lots of people are going on the outing.”
“There are lots of animals in the park.”

However, the two phrases are so closely related that a lot of native speakers use them interchangeably.
However, the two phrases are so closely related that lots of native speakers use them interchangeably.