Mrthoth will show you how to use, count, and mass nouns correctly. Listen to a sample sentence and try to find the grammatical errors in the sentence. A mass noun ca refers to a whole group of objects, for example you would not say a lot of butter you say a lot of butter. A count noun is basically a noun you can count. You can make it plural and you can put a number in front of it. Like you say it was a lot of pencils.