How much cash do you have right now? Five cashes, twenty-two cashes?
No, you might have a lot of cash, twenty-two dollars....
That's because you can't count cash. It's a grammatical thing. English nouns come in two categories: countable and uncountable.
Countable nouns are usually the names of objects, concepts, people, and things that can be enumerated: books, potatoes, teachers, etc.
Uncountable nouns are usually liquids, materials, abstractions, languages, collections, and other things that do not occur separately: milk, information, sugar, advice, copper, weather, flu, etc.
(A few things, like stone, time, space, wine, and room, can be both countable and uncountable, and often their meaning changes depending on their use: We are out of room. We have seven rooms in our house.)
With uncountable nouns, you can use words like a little, a lot of, much, some, hardy any, no or classifiers like a pound of, a bottle of. For example: I have a bottle of wine. I have a little crackers and cheese. I have a lot of trouble planning parties. But you can't say: I have many cash. I have learned a few French.
With countable nouns, you can use words including a lot of, many, a few, some, and any. You can also make the nouns plural: You had a few dollars. Can you buy some apples? You will find many chairs and a few tables in the workroom. But you can't say: You have much teachers. You own little bluejeans.
If you're a native speaker, of course, you know all this automatically. That's because we don't think about grammar when we speak, we remember the groups of words that express our intent. An alert person who grows up surrounded by educated speakers could use perfect grammar without ever studying it.
But if you're learning English, countable and uncountable nouns will be yet another annoying detail to memorize and a source of frequent error.
Is English a difficult language to learn? Yes and no. It starts easy, with fairly direct grammar, and even if you say, "She want to eat many cheese for lunch," people are likely to understand you. But then English gets complex, with various classes of nouns, an excessive number of prepositions, confusing phrasal verbs, tricky participle phrases, and an infinite vocabulary.
So, after all these years, I still study grammar, if only to understand why I use the words I do.
— Sue Burke
Also posted at my writing website: http://www.sue.burke.name