number or amount

Dear Mike,

Hi. Please consider the following: 

amount (noun) [uncountable and countable] a quantity of something such as time, money or substance

number (noun) [uncountable and countable] an amount of something that can be counted 

As mentioned above, you can see that amount denotes quantity of something while number indicates amount of something that can be counted. So, in your sentence: “The total amount (or number?)  of prepositions appearing in one paragraph can also be determined.”, we must choose number as it talks about an amount that can be counted, preposotions. 

Hi Mike,

Use amount when you are interested in “how much”—how much money, fruit, labor, or anything else. It is related to a singular noun. Use number when you are interested in “how many”—how many lemons, people, hyphens, or other items. It is related to a plural noun.

Is "no amount of somenthing" use for emphasis on negativity?
Could you tell me some examples like this?