keep back
2 meanings
not tell someone something you know
What does "keep back" mean in this sense?
Examples
- I could tell she was keeping something back — she wouldn't meet my eyes.
- He admitted that he had kept the full details back from his lawyers.
- Are you sure you're not keeping anything back from me?
How to use it
The most common pattern, with the object placed between 'keep' and 'back'. Pronoun objects and indefinite words like 'something' always go in this position.
I could tell she was keeping something back, but she refused to say what.
Adding 'from + person' makes clear who is not being told — this is extremely common and makes the sentence feel complete.
He had been keeping the real reason back from his colleagues for weeks.
When the object is a longer noun phrase, it can appear after 'back', though the separated form is still often preferred.
The company decided to keep back the full details of the investigation.
The passive is natural when the focus is on the information being withheld rather than on who is withholding it.
Crucial details were kept back from the public during the inquiry.
This phrasal verb frequently appears in sentences involving perception or suspicion — someone can tell, sense, or suspect that another person is not being fully honest.
The interviewer suspected that the witness was keeping something back.
Common Collocations
Common Mistakes
When the object is a pronoun (it, them) or a word like 'something', it must go between 'keep' and 'back', never after 'back'. Placing it after 'back' sounds unnatural in this sense.
'Cover up' implies deliberately hiding something dishonest or scandalous, while 'keep back' is more neutral — someone might keep information back out of caution or kindness, not necessarily deception. Don't treat them as always interchangeable.
When you want to say who is not being told something, you need 'from' before that person. Leaving it out or using a different preposition sounds wrong.
Usage
This phrasal verb is neutral in register and works naturally in both spoken conversation and written contexts like journalism or fiction. It is very commonly followed by 'from' + person to show who is being kept in the dark.
stop someone from moving forward or making progress
Sense 2: What does "keep sb back" mean?
Examples
- Officers struggled to keep the angry protesters back as the march approached the parliament building.
- The barriers were there to keep back spectators during the race.
- The children wanted to rush forward, but their teacher kept them back until it was safe to cross.
How to use it
The most common separated form, used with noun objects such as groups of people or physical forces.
Security guards struggled to keep the crowd back as the gates opened.
When the object is a pronoun, it must go between 'keep' and 'back' — placing it after 'back' is not correct.
The fans surged forward but the stewards managed to keep them back.
The unseparated form is also natural with noun objects, especially in more formal or journalistic writing.
Police deployed extra officers to keep back protesters near the city hall.
The passive form works well when the focus is on the group being restrained rather than on who is doing the restraining.
Spectators were kept back by a row of metal barriers along the route.
These constructions describe how easy or hard it is to prevent forward movement, and are especially common in news contexts.
It was becoming difficult to keep back the floodwaters as the river continued to rise.
Common Collocations
Common Mistakes
When the object is a pronoun, it must go between 'keep' and 'back'. Placing it after 'back' is ungrammatical in English.
'Keep back' and 'hold back' are very similar, but 'hold back' is more versatile — it can describe restraining emotions, withholding effort, or suppressing a reaction. 'Keep back' in this sense is more grounded in physical situations involving people or forces moving forward. In emotional or figurative contexts, 'hold back' is the more natural choice.
'Keep out' means to prevent someone from entering a space, while 'keep back' means to prevent someone from advancing from where they already are. They describe different directions of movement and are not interchangeable.
Usage
This phrasal verb is neutral in register and common in news and everyday contexts, especially for describing crowd control or physical restraint. It is very similar to 'hold back' — both are acceptable, but 'hold back' is more widely used in emotional and figurative situations.
Frequently Asked Questions
Does 'keep back' always suggest someone is being dishonest?
Not necessarily. 'Keep back' can be quite neutral — someone might keep information back to protect another person, to avoid causing worry, or simply because the moment doesn't feel right. It only implies dishonesty when the context makes that clear.
What's the difference between 'keep something back' and 'hold something back'?
'Hold back' is a near-synonym in this sense and you can often use either one. However, 'hold back' is more versatile — it's also used for suppressing emotions or restraining progress — while 'keep back' is more specifically about not telling someone something. In information-withholding contexts, both work naturally.
Can I use 'keep back' without mentioning what is being withheld?
Yes, and this is actually very natural. Saying 'I think he's keeping something back' or 'she kept nothing back' are both common patterns. The indefinite word 'something' is especially frequent and idiomatic in this phrasal verb.
Is there a difference between 'keep the truth back' and 'keep back the truth'?
Both are grammatically possible, but 'keep the truth back' (separated form) is more natural in everyday English. The unseparated form 'keep back the truth' sounds more formal or literary, and is more likely to appear with longer or more complex noun phrases.
Can 'keep back' be used about feelings, not just facts?
Yes — it's natural to say someone is keeping their feelings back from another person, as long as the idea is that those feelings are not being communicated or expressed. The core meaning is about withholding something that could be shared, and feelings fit that pattern well.
Can 'keep back' be used for non-human things, like water or fire?
Yes — extending 'keep back' to natural forces is completely natural at B2 level. You can say things like 'keep back the floodwaters' or 'keep back the flames'. The key idea is still sustained restraint against forward movement, which applies just as well to physical forces as to groups of people.
Does 'keep back' always mean preventing physical movement, or can the object be a situation or problem?
In this sense, the object is almost always a person, group, or physical force — something that is literally trying to move forward. If you want to talk about preventing progress in a more abstract sense (like stopping a competitor from gaining ground), 'keep back' can work metaphorically, but 'hold back' tends to sound more natural in those cases.
I know 'keep back' has another meaning. How do I know which one is being used?
Context makes it clear. In the sense covered here, the object is always a person, group, or physical force being prevented from advancing. The other common sense of 'keep back' involves withholding something — like information or money — where no movement is involved at all.
Is 'keep back' more common in spoken or written English?
It appears naturally in both. You will often see it in news articles reporting on crowd control or protests, and you will also hear it in everyday spoken English — for example, a teacher telling students to stay behind a line. It is neutral in tone and fits comfortably in both contexts.
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