adverb
Etymology
Origin of certainly
Explanation
Use the adverb certainly when you’re sure about a particular action — absolutely, positively sure. If you love the new shoes you just bought, you may defend your purchase by saying they were certainly worth the money you paid. The word certainly emphasizes that you’re positive about something. When you hear thunder and look up at a gray sky, you might say it will certainly rain. If you’re on a diet, you could say that you will certainly avoid chocolate cake. Certainly can also be used to answer a question in the affirmative. If your boss asks to speak to you, you might answer, “Certainly.” It’s just a formal way of saying “yes.”
Vocabulary lists containing certainly
Florida's B.E.S.T. Common Suffixes: -ly
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"Alice's Adventures in Wonderland" by Lewis Carroll, Chapters 4–6
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Novel Study: Barrio Boy, Parts 1–3
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
But again, I think that working at all those different shows that weren’t that good, and certainly were unhappy, each one taught something else.
From Salon • Jul. 5, 2026
And certainly the official title would seem to confirm that.
From The Wall Street Journal • Jul. 4, 2026
Cape Verde may have been the World Cup's smallest nation, but they have certainly made a big impact.
From BBC • Jul. 4, 2026
"I certainly wouldn't have come up with that myself," he laughs when asked about his nickname.
From BBC • Jul. 3, 2026
People often said that the king loved gold more than anything, but certainly not more than his own son, his heir.
From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
