There are many expressions used to express large amounts in English. In general, 'much' and 'many' are the standard quantifiers used to express large quantities.
'Much' is used with uncountable nouns:
There is much interest in learning English around the world.
How much money do you have?
There isn't much butter left in the refrigerator.
'Many' is used with countable nouns:
There are many people who use the computer every day.
How many students live close to the school?
There aren't many books on that shelf.
The following expressions are often used in place of 'much' and 'many', especially in positive sentences.
a lot of
a great deal of
a large number of
the majority of
These expressions can are combined with 'of' in the sense of 'most', 'many' or 'much'.
A lot of people enjoy listening to jazz.
A great deal of time is spent understanding these issues.
Note that 'much', 'most' and 'many' does NOT take 'of'.
Most people enjoy listening to some type of music. (NOT: Most of people...)
Much time is spent understanding math. (NOT: Much of time is spent ...)
Formal / Informal
'A lot of / lots of / plenty of' are generally used in informal situations:
There will be a lot of food at the party.
There's plenty of time to finish your homework.
'A large amount of / a great deal of / a large number of / a majority of' are used in more formal situations, such as written business English and presentations.
There is a great deal of pressure to finish this project on time.
There are a large number of individuals who prefer to do banking online.
Countable / Uncountable
'A lot of / lots of / plenty of' are used with both countable and uncountable nouns.
There's a lot of juice in this jug.
There are plenty of opportunities to learn online.
There are lots of people who like chess.
'A large amount of / a great deal of' are used with uncountable nouns such as 'water, money, time, etc.'
There's a large amount of work to be done on this project.
There isn't a great deal of time to finish this report.
'A large number of / a the majority of' are used with countable nouns such as 'people, students, investors, etc.'
The majority of investors are interested in low-risk opportunities.
A large number of our pupils continue their studies at university.