certainly

certainly — adverb

1. used to say that something is definitely true and there is no question about it

1.副詞A2
釋義

used to say that something is definitely true and there is no question about it at all

例句

The children certainly enjoyed their trip to the farm yesterday.

certainly + verb (emphasises the statement)

Kofi certainly runs faster now than he did last spring.

subject + certainly + verb + comparative

同義詞
  • definitely

    more common in everyday speech, equally strong

  • undoubtedly

    more formal, often used in writing

  • absolutely

    used for emotional emphasis, common in conversation

反義詞
  • possibly

    adds doubt instead of removing it

  • maybe

    expresses uncertainty, A1-level alternative

文法句型

certainly + verb

certainly + modal + verb

subject + certainly + verb

用法筆記

Placed directly before the main verb in a simple sentence (She certainly sings well) or after the first auxiliary verb in a verb phrase (He has certainly improved). When placed at the start of a clause, it adds extra emphasis to the whole statement.

常見錯誤

❌Surely I passed the test — I got every answer right.
✅Certainly I passed the test
💡I got every answer right.' — 'Surely' expresses expectation with some doubt, while 'certainly' removes all doubt and states a fact.

2. used to give a very clear yes or no when someone asks you to do something or ask

2.副詞A2
釋義

used to give a very clear yes or no when someone asks you to do something or asks for permission

例句

"May I use your phone?" "Certainly, please go right ahead."

one-word response agreeing to a request

"Could you feed my cat while I am away?" "Certainly, I will be happy to."

同義詞
  • of course

    equally common in both UK and US English, slightly less formal

  • absolutely

    stronger emotional tone, used for enthusiastic agreement

  • sure

    informal, very common in American English

反義詞
  • no

    direct opposite, but less polite for refusing a request

  • never

    strong refusal, more emotional than 'certainly not'

文法句型

'Certainly.' (agreeing)

'Certainly not.' (refusing)

'Certainly, [clause]'

用法筆記

This sense occurs almost exclusively in spoken conversation or direct dialogue. 'Certainly not' is a polite but firm way to say no to a request. 'Certainly' alone conveys willing agreement. Less common in American English than in British English, where 'Sure' is often preferred.

常見錯誤

❌Teacher: Can you help me carry these books? Student: Yes, certainly I can help.
✅Teacher: Can you help me carry these books? Student: Certainly.
💡As a reply, 'certainly' alone is natural; adding 'yes' before it is redundant.

3. used to say that something is almost sure to happen or is very probably true

3.副詞
釋義

used to say that something is almost sure to happen or is very probably true

例句

The price of milk will certainly go up again next month.

will certainly + verb (future probability)

If no one stops him, Rohan will certainly eat the whole cake by himself.

同義詞
  • undoubtedly

    more formal, equally strong in meaning

  • inevitably

    suggests something cannot be avoided, slightly more negative

  • surely

    expresses expectation rather than certainty, weaker

反義詞

文法句型

will certainly + verb

certainly + present tense

be certainly + past participle

用法筆記

Unlike sense 1 (WITHOUT DOUBT), this sense does not express the speaker's own emphasis — it expresses a prediction about what is almost sure to happen. The structure 'will certainly + verb' is the most common pattern. Distinguish from sense 1: in 'I certainly hope so' (sense 1) the speaker is emphasising their feeling; in 'It will certainly rain' (sense 3) the speaker is predicting what will happen.

常見錯誤

❌He certainly will be late again, I am sure of it.
✅He will certainly be late again, I am sure of it.
💡With 'will', the natural word order is 'will certainly + verb' not 'certainly will + verb', though both are sometimes used.