Many students who are learning English are very surprised to learn that the words information, knowledge, and jewelry have no plural forms. These are called uncountable noums: Here is my list so far: accommodationadvicebaggagebreadbraverychaosclaritycouragecowardiceequipmenteducationevidencefurnituregarbagegreedhomeworkhonestyinformationjewelryknowledgelivestockluggagemarketingmoneyinsurancemudnewspastapatriotism (and the other -ism words)progressracismresearchsexismtravelweatherwork