Supposedly vs. Supposably – Which is Correct?

Spoken and written English differ in many important ways. Regional differences in pronunciation, the level of familiarity between speakers, and the overall context of the conversation all contribute to these differences.

Most people consider spoken language less formal than written language, so many things that people get away with when speaking would be considered serious mistakes on the page. If you have ever transcribed a recording of a conversation, you are aware how awkward spoken English actually looks in writing.

Many people pronounce the adverb supposedly as supposably when saying it out loud. Is this pronunciation an accepted variant of the word, or a mistake? Continue reading to learn more.

What is the Difference Between Supposedly and Supposably?

In this post, I will compare supposedly vs. supposably. I will use outline which of these spellings is correct and demonstrate its proper use in the English sentence with definitions and examples.

Plus, I will show you a memory tool that you can use to choose supposably or supposedly in your own writing.

When to Use Supposedly

Definition of supposably definition of supposedly definitionWhat does supposedly mean? Supposedly is an adverb. It means assumed to be true.

Here are a few examples,

  • Cecilia’s is supposedly the best pizza in town, but last time we went there, the crust was badly burned.
  • Clayton Kershaw is supposedly the best pitcher in baseball, but he has not won the Cy Young award since 2014.

Adverbs modify verbs by describing how the action was performed. Most adverbs are obvious because they end in the suffix -ly. A person could cook skillfully, or sleep soundly.

In the sentences above, supposedly modifies the verb is. Instead of a simple statement of truth (Clayton Kershaw is the best pitcher in baseball), the example becomes a statement of assumed truth (Clayton Kershaw is supposedly the best pitcher in baseball).

Here is another example,

  • The Wall Street Journal reports on the unsettling new trend of bosses moving past the stuffy old handshake in favor of a hug, which supposedly makes for a more pleasant, caring workplace. –New York Magazine

When to Use Supposably

Define supposably and define supposedlyWhat does supposably mean? Supposably is a misspelling of supposedly, probably based on the mispronunciation of the latter in spoken English.

As you can see from the below graph, which charts supposably vs. supposedly in English books, most writers avoid the spelling entirely.

supposedly versus supposably

In fact, supposably is used so infrequently that it barely registers a blip on the screen.

How to Pronounce Supposedly

Since most of the confusion around these words has to do with the pronunciation over the word, it makes sense to go through the proper way to pronounce supposedly.

Its pronunciation is pretty phonetic: suh-poez-ed-ly.

The important thing to remember from a pronunciation standpoint is that there is no “A” or “B” is supposedly.

Trick to Remember the Difference

how to spell supposedIt’s not difficult to differentiate these spellings since only one of them in used in written English.

  • Supposedly is the correct spelling.
  • Supposably is a misspelling.

You can help yourself remember that supposedly is the correct word to use since it contains a D, like adverb. Supposedly is an adverb, so the shared D between these words is your clue that it is the correct choice.


Is it supposedly or supposably? Supposedly is an adverb that means assumed to be true. Supposably is a misspelling of supposedly.