Uncountable nouns in Welsh grammar are interesting because, unlike many languages, Welsh has certain rules and patterns to identify them. These uncountable nouns, also known as mass nouns, do not come in plural form and cannot be counted using numbers. They usually represent materials, liquids, collections or abstract ideas. In Welsh, many uncountable nouns have affixed endings that can be learned to recognize them more easily. The practice below would help you to understand these rules and eventually use them fluently in regular conversation.