Also found in: Thesaurus, Idioms, Wikipedia.


1. Undoubtedly; definitely: This is certainly not my writing.
2. By all means; of course: You may certainly join us.
3. Surely: They certainly are hard workers.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


with certainty; without doubt: he certainly rides very well.
sentence substitute
by all means; definitely: used in answer to questions
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈsɜr tn li)

1. without doubt; assuredly: I'll certainly be there.
2. yes, of course: Certainly, take the keys.
3. surely; to be sure: She certainly is successful.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


1. emphasizing and agreeing

Certainly is used to emphasize statements. You often use certainly when you are agreeing with something that has been said or confirming that something is true.

It certainly looks wonderful, doesn't it?
Ellie was certainly a student at the university but I'm not sure about her brother.

Be Careful!
Don't confuse certainly and surely. You use surely to express disagreement or surprise.

Surely you care about what happens to her.

Both British and American speakers use certainly to respond positively to a question or statement.

'Do you see this as a good result?' – 'Oh, certainly.'

American speakers also use surely in this way.

'Can I have a drink?' – 'Why, surely.'
2. position in sentence

Certainly is usually used to modify verbs.

If there is no auxiliary verb, you put certainly in front of the verb, unless the verb is be.

It certainly gave some of her visitors a fright.

If the verb is be, certainly can go either in front of it or after it. It usually goes after it.

That certainly isn't true.

If there is an auxiliary verb, you usually put certainly after the auxiliary verb.

He'd certainly proved his point.

If there is more than one auxiliary verb, you usually put certainly after the first one. Certainly can also go in front of the first auxiliary verb.

He will certainly be able to offer you advice.
The roadway certainly could be widened.

If you use an auxiliary verb without a main verb, you put certainly in front of the auxiliary verb.

'I don't know whether I've succeeded or not.' – 'Oh, you certainly have.'

You can also put certainly at the beginning of a sentence.

Certainly it was not the act of a sane man.
3. 'almost certainly'

If you think that something is true, but you are not quite sure about it, you can use almost certainly.

She will almost certainly be left with some brain damage.

Be Careful!
Don't put 'nearly' in front of certainly.


1. 'surely'

You use surely for emphasis when you are objecting to something that has been said or done.

'I can have it ready for next week.' – 'Surely you can get it done sooner than that?'
Their lawyers claim that they have not broken any rules, but surely this is not good practice.
2. 'definitely' and 'certainly'

Don't use 'surely' simply to give strong emphasis to a statement. Use definitely.

They were definitely not happy.
The call definitely came from your phone.

In British English, you don't use 'surely' when you are agreeing with something that has been said, or confirming that something is true. Use certainly.

Ellie was certainly a student at the university but I'm not sure about her brother.
'You like him, don't you?' – 'I certainly do.'

American speakers use both surely and certainly to agree with requests and statements.

'It is still a difficult world for women.' – 'Oh, certainly.'
Surely, yes, I agree with that.

Don't use 'surely' to say emphatically that something will happen in the future. Use definitely or certainly.

The conference will definitely be postponed.
If nothing is done, there will certainly be problems.
3. 'naturally'

Don't use 'surely' to emphasize that something is what you would expect in particular circumstances. Use naturally.

His sister was crying, so naturally Sam was upset.
Naturally, some of the information will be irrelevant.
Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adv.1.certainly - definitely or positively (`sure' is sometimes used informally for `surely'); "the results are surely encouraging"; "she certainly is a hard worker"; "it's going to be a good day for sure"; "they are coming, for certain"; "they thought he had been killed sure enough"; "he'll win sure as shooting"; "they sure smell good"; "sure he'll come"
colloquialism - a colloquial expression; characteristic of spoken or written communication that seeks to imitate informal speech
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002


The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
بالتَّأكيدبِلَا شَكّطَبْعاً!طَبْعا، بالتَّأكيد
bestemthelt bestemthelt sikkertselvfølgelig
بطور محرز
Auîvitaî, aî sjálfsögîuvissulega, aî sjálfsögîuvissulega, áreiîanlega
chắc chắn


[ˈsɜːtənlɪ] ADV
1. (= undoubtedly) → con toda certeza, sin duda alguna
if nothing is done there will certainly be an economic crisissi no se hace nada, con toda certeza or sin duda alguna se producirá una crisis económica
your answer is almost certainly rightcasi seguro que or casi con seguridad tu respuesta está bien
it is certainly true thatdesde luego es verdad or cierto que ...
2. (= definitely) something should certainly be done about thatdecididamente, deberían hacer algo al respecto
I will certainly get it finished by tomorrowdefinitivamente lo termino para mañana
it's certainly betterdesde luego es mucho mejor
this computer is certainly an improvement on the old oneeste ordenador es sin ninguna duda mejor que el antiguo
it certainly impressed meya lo creo que me impresionó
I shall certainly be thereno faltaré, seguro que estaré
you certainly did that welldesde luego eso lo hiciste bien
I would certainly like to trydesde luego (que) me gustaría probar
such groups most certainly existesos grupos existen con toda seguridad
3. (in answer to questions, requests) "could you give me a lift?" - "certainly!"-¿me podrías llevar? -¡claro (que sí)! or ¡por supuesto! or ¡faltaría más!
certainly madam!¡con mucho gusto, señora!, ¡por supuesto, señora!
"wouldn't you agree?" - "oh, certainly"-¿estás de acuerdo? -sí, desde luego
"had you forgotten?" - "certainly not"-¿se le había olvidado? -por supuesto que no or claro que no
"would you ever eat snake?" - "certainly not!"-¿comerías serpiente? -¡qué va!
"will you accept his offer?" - "certainly not!"-¿vas a aceptar su oferta? -¡qué va! or ¡de ninguna manera!
"can I go on my own?" - "certainly not!"-¿puedo ir sola? -¡de eso nada! or ¡ni hablar!
4. (= granted) certainly, she has potential, butdesde luego tiene posibilidades, pero ..., no hay duda de que tiene posibilidades, pero ...
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005


[ˈsɜːrtənli] adv
(= definitely) [seem, appear] → certainement; [think, expect] → vraiment
I certainly expected something better → Je m'attendais vraiment à quelque chose de mieux.
So it was a surprise? - It certainly was!
BUT C'était donc une surprise? - Ça oui alors!.
certainly not! → certainement pas!
it's certainly true that ... → il ne fait aucun doute que ...
(= of course) → bien sûr
Collins English/French Electronic Resource. © HarperCollins Publishers 2005


adv (= admittedly)sicher(lich); (= positively, without doubt)bestimmt, gewiss (geh); it is certainly true that …es ist sicherlich richtig, dass …; certainly not!ganz bestimmt nicht, auf keinen Fall!; I certainly will not!ich denke nicht daran!; certainly!sicher!, gewiss! (geh)
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007


[ˈsɜːtnlɪ] advcertamente, certo
certainly! → (ma) certo!
certainly not! → no di certo!
I shall certainly be there → ci sarò sicuramente, ci sarò certamente
Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995


(ˈsəːtn) adjective
1. true or without doubt. It's certain that the world is round.
2. sure. I'm certain he'll come; He is certain to forget; Being late is a certain way of losing one's job.
3. one or some, not definitely named. certain doctors; a certain Mrs Smith; (also pronoun) certain of his friends.
4. slight; some. a certain hostility in his manner; a certain amount.
ˈcertainly adverb
1. definitely. I can't come today, but I'll certainly come tomorrow.
2. of course. You may certainly have a chocolate.
of course. `May I borrow your typewriter?' `Certainly!'; `Certainly not!'
ˈcertaintyplural ˈcertainties noun
1. something which cannot be doubted. It's a certainty that he will win.
2. freedom from doubt. Is there any certainty of success?
for certain
definitely. She may come but she can't say for certain.
make certain
to act so that, or check that, something is sure. Make certain you arrive early; I think he's dead but you'd better make certain.
Kernerman English Multilingual Dictionary © 2006-2013 K Dictionaries Ltd.


بِلَا شَكّ jistě bestemt sicher οπωσδήποτε ciertamente, definitivamente varmasti certainement sigurno certamente 確かに 확실히 beslist sikkert na pewno certamente конечно säkert อย่างแน่นอน kesinlikle chắc chắn 的确
Multilingual Translator © HarperCollins Publishers 2009
References in classic literature ?
SOCRATES: We have certainly, as would seem, assisted him in some degree to the discovery of the truth; and now he will wish to remedy his ignorance, but then he would have been ready to tell all the world again and again that the double space should have a double side.
MENO: I certainly thought just now that we were right.
But howsoever it be between nations, certainly it is so between man and man.
Certainly we will, said Glaucon; and in a few minutes Polemarchus appeared, and with him Adeimantus, Glaucon's brother, Niceratus the son of Nicias, and several others who had been at the procession.
Yes, said Polemarchus, and not only so, but a festival will he celebrated at night, which you certainly ought to see.
And certainly there is much in the book, thus effectively presented to the English reader, to attract those who interest themselves in the study of the finer types of human nature, of literary expression, of metaphysical and practical philosophy; to attract, above all, those interested in such philosophy, at points where it touches upon questions of religion, and especially at the present day.
"'You are certainly very thoughtful about others,' answered the Wife, as she sat in her comfortable armchair by the big pinewood fire; 'very thoughtful indeed.
We returned a suitable answer to this affectionate Note and after thanking her for her kind invitation assured her that we would certainly avail ourselves of it, whenever we might have no other place to go to.
I only say that I'll certainly go with you," said Petya shyly.
"Anne, this is certainly your night for looking handsome.
Jones now declared that they must certainly have lost their way; but this the guide insisted upon was impossible; a word which, in common conversation, is often used to signify not only improbable, but often what is really very likely, and, sometimes, what hath certainly happened; an hyperbolical violence like that which is so frequently offered to the words infinite and eternal; by the former of which it is usual to express a distance of half a yard, and by the latter, a duration of five minutes.
"Certainly not; but if you observe, people always live for ever when there is an annuity to be paid them; and she is very stout and healthy, and hardly forty.