Adjective / Verb A2 — Elementary /ˈəʊ.pən/

Open — Definition, Examples & Usage

Not closed, not restricted — one of the most versatile words in English.

Quick Definition

Open (adjective): not closed; not blocked; available to all or not restricted. The window is open.

Open (verb): to move something to a position that is no longer closed; to start something. The shop opens at nine o'clock every morning.

What Does Open Mean?

Open is one of the most common and most versatile words in the English language. As an adjective it describes something that is not closed, sealed, or blocked: an open door, an open wound, an open mind. It can also mean not restricted or freely available: an open competition, an open invitation.

As a verb, open describes the action of moving something from a closed to an open position — opening a door, opening a jar, opening a file. It also means to start or inaugurate: a film that opens in January, a minister who opens a new hospital, a speech that opens with a joke.

The same spelling serves both functions, and learners must rely on context to identify the part of speech. Compare: The café is open (adjective — describes the current state) and The café opens at eight (verb — describes an action or regular event).

Etymology: From Old English open (adjective) and openian (verb), derived from Proto-Germanic *upanaz, related to the word up. The original sense was of something raised or lifted — like a lid being lifted off. Cognates include German offen and Dutch open. The word has been in continuous use in English for more than 1,000 years and gave rise to the suffix -open in compounds such as wide-open and half-open.

Example Sentences (A2–C1)

SentenceLevel & usage note
The shop opens at nine o'clock every morning. A2 — verb, present simple, describing a routine
Please leave the back door open so the cat can get in. B1 — adjective, predicate position after 'leave'
She opened the envelope carefully and read the letter inside. B1 — verb, past simple, describing a single completed action
The new gallery will open to the public next spring. B2 — verb with prepositional phrase 'open to', future reference
The report leaves the question of funding open to further negotiation. C1 — adjective in complex nominal phrase; formal/written register

Common Collocations

CollocationExample
wide openThe front door was wide open when we arrived.
open an accountYou can open a bank account online in minutes.
keep an open mindTry to keep an open mind before you make a decision.
open to suggestionsWe are completely open to suggestions from the team.
open secretIt was an open secret that the firm was struggling.
open-endedThe teacher asked an open-ended question to encourage discussion.
open fireThe officers were ordered not to open fire unless necessary.
in the openThe children spent most of the afternoon playing in the open.
open armsThey welcomed the refugees with open arms.
open-mindedYou need to be open-minded when living abroad.

Usage Notes

A very common learner error is to use opened when describing a state rather than an action. In British English, use the adjective open (not the past participle opened) to describe something that is currently in an open state.

Common Mistakes

The window is opened. (describing a state)

The window is open. (correct — adjective for a state)

She open the letter yesterday.

She opened the letter yesterday. (correct — past simple verb)

Note also that open as a verb is intransitive in some contexts (The door opened slowly) and transitive in others (She opened the door slowly). Both patterns are correct; the meaning is similar but the focus differs — the intransitive form focuses on the door itself, while the transitive form emphasises the agent performing the action.

Related Words

openly openness opener opening open-minded open-plan reopen wide-open

Synonyms & Antonyms

Adjective synonyms:

unlocked ajar accessible unrestricted available exposed

Antonyms:

closed shut locked restricted sealed

Related Vocabulary

All Common Words → Grammar Glossary Vocabulary Hub Flash Cards

Practise This Word

Flash Cards Complete the Sentence Vocabulary Quiz Hangman

Frequently Asked Questions about “open”

What does open mean in English?
Open has two main meanings. As an adjective it means not closed, not blocked, or freely available: 'The door is open.' As a verb it means to move something so that it is no longer closed, or to start something: 'Please open the window.' It is one of the most common words in English and appears in hundreds of everyday phrases.
Is open an adjective or a verb?
Open is both an adjective and a verb, and context tells you which. 'The shop is open' uses open as an adjective (predicate adjective after the verb 'is'). 'Can you open the door?' uses open as a verb. It can also function as a noun ('the open air', 'in the open') and in compound adjectives ('open-minded', 'open-plan').
What is the difference between open and opened?
Open (adjective) describes a state: 'The window is open.' Opened is the past tense or past participle of the verb: 'She opened the window.' The two are often confused. Use 'open' for the current condition and 'opened' to describe the action. Never say 'The door is opened' when describing a state — say 'The door is open'.
What are the most common collocations with open?
Common verb + open collocations include: open a door/window, open an account, open a meeting, open fire, open negotiations. Common adjective patterns include: wide open, half open, openly available. Fixed expressions include: in the open, open to suggestions, open-ended, keep an open mind, open secret, open arms.
What does 'open to' mean?
'Open to' means willing to consider or accept something: 'I am open to new ideas.' It can also mean exposed to or liable to: 'This policy is open to criticism.' The phrase 'open to suggestions' is extremely common in business English and signals that the speaker is willing to hear other opinions.
What is the difference between open and public?
Open emphasises the absence of restriction or barriers ('The competition is open to everyone'). Public emphasises that something belongs to or is provided for the general community ('a public library'). A public event is usually open to all, but an open event stresses the lack of entry requirements rather than public ownership.
What is the etymology of the word open?
Open comes from Old English 'open' (adjective) and 'openian' (verb), both from Proto-Germanic *upanaz, related to 'up'. The root idea is of something raised or lifted — think of a lid being lifted off. The word is related to the German 'offen' and Dutch 'open'. It has been in continuous use in English for over 1,000 years.
What does 'open secret' mean?
An open secret is something that is supposed to be confidential but is actually known by many people: 'It was an open secret that the company was in financial difficulty.' The phrase is slightly ironic — a secret by definition should not be known, so calling it 'open' highlights the contradiction. It is a useful collocation for C1-level learners.
How do you use open as a noun?
Open as a noun usually appears in fixed phrases. 'In the open' means outdoors or no longer hidden: 'The children love playing in the open.' 'Out in the open' means known publicly: 'It is good to get these concerns out in the open.' 'The Open' (with capital O) refers to major golf tournaments such as The Open Championship.
How can I practise using open in English?
Try LexFizz's Complete the Sentence exercise to practise open in context, or use Flash Cards to test vocabulary including open and its related forms (openly, openness, open-minded, reopen). Writing short sentences using the collocations table above is also an excellent low-tech practice method.