Learning about how and when to use certain prefixes can help learners to get a better grasp at the target language’s vocabulary. This study analyzes the meaning and usage of not only English negation in- and un-, but also Japanese negation prefixes fu- and mu-, which frequently used in various situations. They are compared to get a better understanding of the similarities and differences between those pairs of negative prefixes from two different language. This study uses descriptive qualitative approach with data taken from newspaper articles, both in English and Japanese, in the form of sentences which included words attached with the prefixes. It is found that while quite similar in some aspect, such as meaning and morphology, they also have differences in that very aspect and more. The differences found not only when comparing the English prefixes with the Japanese’s, but also when comparing both pairs with one another.