Amongst the many words in English that are similar in sound but vastly different in meaning includes “supposedly” and “supposably”. Although “supposedly” is more commonly used, and “supposably” causes a red flag in Word processor grammatical checks, the two are actually real words. Their definitions are similar enough to cause additional confusion in understanding how to use each word properly.
“Supposedly” refers to something that can be assumed or generally believed accordingly. For example, “I will supposedly have enough time to finish my assignment later”. In this sentence, “supposedly” serves to imply a potential for something to happen, yet there is no guarantee that it will actually happen in that way. Another example would be “He supposedly told them the event was at 9am, but I recall him saying 10am”. In this example, the implication is that one group of people claim one thing as having been said which is being questioned by someone who remembers a different story.
On the other hand, “supposably” is something that is capable of being supposed. In other words, the idea of said thing is conceivable or possible. Although this word is much rarer than “supposedly”, it is an adjective form of the word “suppose” or “supposable”. The word’s Latin origins imply that “supposably” and its related forms are developed from language describing “to substitute” or “to place below”.
This word is just one of many examples in the English language where subtle differences in spelling and meaning can completely alter attempts for communication.