"Many" and "a lot of"

NM Liang asked if the sentence, "I have many coin," is correct.

No, this sentence is not correct, because the word many is used with plural nouns, only, and coin is a singular noun.

The plural of coin is coins. Therefore, the correct sentence would be:

• I have many coins. 

With a noncount noun, such as gold, which has no plural form, use "a lot of," as in this example:

• I have a lot of gold. 

I hope this helps.