# certain

/ˈsɝtən/ (US) · /sˈɜːtən/ (UK)

Source: https://englishreference.com/word/certain
Updated: 2026-06-19

## Senses

### 1. sure or confident

adjective · CEFR A2

to be completely sure about something in your mind.

For teachers: convinced of the truth of a particular fact or idea; possessing no doubt.

- I am certain that I locked the front door before we left.
- The researchers are certain of their findings, having replicated the experiment under controlled conditions three times.

### 2. inevitable

adjective · CEFR B1

sure to happen; something that cannot be avoided.

For teachers: inevitable or destined to occur; established as a factual certainty.

- It is certain that the sun will rise tomorrow morning.
- Failure was almost certain once the primary engine lost pressure during the ascent.

### 3. specific but unnamed

determiner · CEFR B1

used to talk about a particular person or thing without giving their name or exact details.

For teachers: referring to a specific but unspecified individual, group, or thing; often used to introduce a topic without exhaustive detail.

- A certain person told me that you were looking for a new job.
- There are certain risks involved in this investment that we must discuss before signing the contract.

### 4. limited or some

adjective · CEFR B2

used to describe a limited amount of a quality, like 'a certain amount of luck'.

For teachers: denoting a limited or definite extent or degree of a quality.

- You need a certain amount of patience to teach young children.
- The project requires a certain level of expertise that the current staff does not yet possess.

### 5. some members of a group

pronoun · CEFR C1 · Formal

some people or things in a group, but not all of them.

For teachers: referring to an unspecified but restricted number of members within a larger set.

- Certain of the guests decided to leave the party early.
- Certain of the documents were found to be forged, casting doubt on the entire legal proceeding.

## Examples

- I am certain that I locked the door.
- The manager was certain of the team's success after seeing their final practice session.
- While the evidence appeared strong, the lead investigator was not yet certain enough to make a formal accusation without further forensic confirmation.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.