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.
Certainly some of that is attributable to the World Cup, but retail excluding gas and dining out was growing almost the same as services.
From Barron's • Jun. 16, 2026
"Certainly here, it ends the night at weddings, it has got a legendary status," he added.
From BBC • Jun. 14, 2026
Certainly Dana White realized he could sell more pay-per-views by playing up personal insults and grudge matches.
From Slate • Jun. 14, 2026
Certainly, none of the kids in this room need to.
From The Wall Street Journal • Jun. 1, 2026
"Muy buenos. Yes, there is a female English. Certainly you can see her if she wishes to see you."
From "The Sun Also Rises" by Ernest Hemingway
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.
