Lock sb up Meaning, Examples & How to Use This Phrasal Verb

What Does “Lock sb up” Mean?

“Lock sb up” means to put someone in a locked place, usually a prison or jail, to keep them confined.

Introduction

The phrase “lock sb up” is a common English phrasal verb used to describe the act of putting someone in a locked room or prison. It often relates to law enforcement or punishment, where a person is confined for safety or legal reasons. Understanding the “lock sb up meaning” helps learners use the phrase correctly in conversations about crime, punishment, or even informal contexts where locking someone in a room might be discussed. This phrase is straightforward but important for expressing ideas about confinement and security.

Quick Info Box

• Phrasal verb: lock sb up (lock somebody up)
• Type: transitive
• Level: B1
• Short meaning: to put someone in prison or a locked place

Structure (Grammar Rules)

“Lock sb up” is a separable phrasal verb. You can place the object (somebody) between “lock” and “up” or after the whole phrase.

• lock somebody up
• lock up somebody

Example patterns:

• Subject + lock + somebody + up
• Subject + lock up + somebody

How to Use “Lock sb up”?

You use “lock sb up” when talking about placing someone in jail or another locked place. It can also be used figuratively, such as locking a child in a room for safety. The phrase often appears in news reports, police stories, and daily conversations about crime or discipline.

Examples

Here are some examples of “lock sb up” in sentences to help you understand its usage:

• The police decided to lock him up after the investigation.
• If you break the law, they will lock you up in jail.
• She threatened to lock her brother up in the basement as a joke.
• The judge said he would lock the criminal up for ten years.
• They had to lock the prisoner up securely before transport.

Common Mistakes

People often confuse the correct placement of the object or misuse the phrase in informal situations.

• Incorrect: They will lock up him tomorrow.
• Correct: They will lock him up tomorrow.
• Incorrect: She locked up the dog outside. (If the dog is not confined, this can be unclear.)
• Correct: She locked the dog up outside in the kennel.

Differences / Synonyms

Similar phrases include “put sb in jail,” “imprison sb,” and “lock sb away.” However, “lock sb up” is more informal and often used in spoken English. “Imprison” is more formal and legal, while “put sb in jail” is straightforward but less idiomatic.

Unlike “lock sb up,” the phrase “lock up” without an object can mean to secure a place by locking doors and windows, not necessarily involving a person.

Common Collocations

Here are some common objects used with “lock sb up” and their meanings:

• Lock a criminal up: to imprison someone who committed a crime.
• Lock a prisoner up: to keep a prisoner confined.
• Lock a suspect up: to detain someone suspected of a crime.
• Lock a child up: to keep a child safely confined (usually informal or joking).

Related Phrasal Verbs

Here are related phrasal verbs of lock sb up:

• Lock Sth Out
• Lock Sb Away
• Lock Sth Up
• Lock Sb Out
• Lock Yourself Out Of Sth

Real-life Dialogue

Here is a short conversation using “lock sb up”:

Tom: Did the police catch the thief?

Anna: Yes, they locked him up last night.

Tom: Good. He shouldn’t be free after what he did.

Practice

Try to complete the sentence with the correct form of “lock sb up”:

1. The judge decided to _______ the dangerous criminal _______ for 15 years.

2. If you break the rules, they will _______ you _______ in the detention room.

3. She joked that she would _______ her little brother _______ in the closet.

FAQs

• What does “lock sb up” mean? It means to put someone in a locked place, usually prison or jail.
• Is “lock sb up” formal or informal? It is mostly informal but common in everyday English.
• Can “lock sb up” be used figuratively? Yes, it can mean to confine someone in a locked room, often jokingly.
• Is “lock sb up” separable? Yes, you can say “lock him up” or “lock up him,” but the first is more common.
• What is a synonym for “lock sb up”? “Put sb in jail” or “imprison sb” are similar.