Yeah, think of it this way. How did you memorize nouns in the first place? You learned the words aspirin, bandages, shaving cream, so you just have to learn the containers the same way. However, if you really want to cheat (hehehehe), we often lazily and apathetically refer to containers as "things", like "pass me a thing of toothpaste" Or pass me one of those things over there. "pass me a thing of water." That said the words Cup and glass are often used for liquids (which are uncountable nouns), and lbs are used frequently (2 pounds of beef please). You can tell by the shape too. (tube of toothpaste cause it comes in a tube. Box is pretty easy to figure out. In fact, I don't say package of tissues, we say "Box of tissues" or box of Klennex. Often things will be in bottles, boxes, or cans (can of paint, can of shaving cream). OH I got it. Cans are metal (can of pop, can of paint, can of shaving cream). Boxes tend to be cardboard (antique stuff is wood). That's all I can think of. Cans are circular and metal. Sorry, there are rules to determine which nouns are Uncountable and thus have to pluralized via with their containers, if that helps.