'Much' is used when we are speaking about a singular noun. 'Many' is used when we are speaking about a plural noun. When we speak about 'many' and 'much', it's worth mentioning countable and uncountable nouns. Countable nouns can be used with a number and have singular and plural forms.

When can I use much?

Use much if the noun is non-countable (e.g., water, sand). Use many if the noun is countable (e.g., oranges, children). For example: I don't have much money.

How do you use the word much?

Use the adjective much to mean "a lot" or "a large amount." If you don't get much sleep the night before a big test, you don't get a lot. If you get too much sleep, you may sleep through your alarm and miss the test. Much is used as an adjective or adverb, but it always means a large quantity, extent, or degree.