English Reference

Phrasal verb

lock up

Irregular verb

Forms

Infinitive

lock up

Past

locked up

Past participle

locked up

Definition

phrasal verb. To make a building or room safe by locking all the doors and windows. You usually do this when you are the last person to leave a place.

phrasal verb. To secure a building or premises by engaging all locks. The verb functions intransitively to describe the act of closing a business for the day or transitively with the building as the object.

Examples

“Don't forget to lock up when you leave the office.”

“The shop owner always stays late to count the money and lock up the store before heading home.”

“After the final performance, the stage manager was tasked to lock up the theater, ensuring all fire exits were clear and the main gates were bolted.”

Examples

simple

“Don't forget to lock up when you leave the office.”

contextual

“The shop owner always stays late to count the money and lock up the store before heading home.”

complex

“After the final performance, the stage manager was tasked to lock up the theater, ensuring all fire exits were clear and the main gates were bolted.”

Usage

This phrase is often used without an object when the location is already known to the speaker.

Teaching tip

Highlight that 'up' adds a sense of completeness to the action, implying that every entrance is secured rather than just one lock.

Phrasal verb

Particles

up

Separability

optional

Pattern

lock + up (+ object)

Synonyms

secureclose upshut up

Antonyms

open upunlock

Word family

VERB

NOUN

ADJECTIVE

PHRASAL VERB

lock up(B1)

Grammar

Phrasal verbs (introduction)

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B1 PreliminaryIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.4.0–5.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 3.0–3.544–71TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.550–784
Frequency
Common
Level
B1 · Intermediate
Updated

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English Reference