Idiom B1 Informal / Semi-formal

Up in the air

Uncertain or not yet decided; a situation whose outcome has not been settled

Meaning

Up in the air — Uncertain or not yet decided; a situation, plan, or arrangement that has not been settled or finalised, so the outcome is still in doubt.

Origin & History

The expression draws on the simple image of something suspended in the air rather than settled or grounded. Just as an object floating above the ground has not yet come to rest, a matter that is "up in the air" has not yet been resolved. The contrast between being airborne and being settled on solid ground makes the metaphor easy to grasp.

The phrase has been used figuratively for unsettled or undecided matters since the late 1700s and 1800s. Over time it became a fixed idiom in everyday English, applied to anything from holiday plans to business deals whenever the outcome remains uncertain.

Example Sentences

SentenceContext
Our holiday plans are still up in the air because we haven't booked the flights yet.Unconfirmed travel plans
The merger is up in the air until the board votes next week.Business decision pending
His future at the club is up in the air after the manager left.Uncertain career situation
Everything is up in the air right now, so we can't confirm a date.General uncertainty
The wedding venue is still up in the air, but we'll decide by Friday.Event planning
With the funding decision up in the air, the project has been paused.Project on hold

How to Use It

This idiom works in both informal conversation and semi-formal contexts such as emails and business discussions. It usually follows a linking verb, as in plans are up in the air or it is still up in the air, and often pairs with words like still or right now to stress that no decision has been made. Use it to describe situations that are genuinely unresolved rather than ones that are simply delayed.

Common Mistakes

Mistakes to Avoid

The plans are up on the air at the moment.

The plans are up in the air at the moment. — Use 'in', not 'on'; the preposition is fixed.

Her future is in the air after the announcement.

Her future is up in the air after the announcement. — Do not drop 'up'; the full phrase is required.

We threw our weekend plans up in the air.

Our weekend plans are up in the air. — It describes a state of uncertainty, not a physical action.

Similar Idioms

In limbo On the fence Hanging in the balance Touch and go All Idioms →

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Frequently Asked Questions

What does "Up in the air" mean?
"Up in the air" means uncertain or not yet decided. It describes a situation, plan, or decision that has not been settled or finalised, so the outcome is still in doubt.
Where does the idiom "Up in the air" come from?
The phrase draws on the image of something suspended in the air rather than settled or grounded. Just as an object floating above the ground has not come to rest, a matter that is 'up in the air' has not been decided. It has been used figuratively for unsettled matters since the late 1700s and 1800s.
Can you give an example of "Up in the air" in a sentence?
Here is an example: "Our holiday plans are still up in the air because we haven't booked the flights yet." — used when arrangements have not been decided or confirmed.
Is "Up in the air" formal or informal?
It can be used in both informal and semi-formal contexts. It is very common in everyday conversation and informal writing, and also appears in business discussions and journalism when describing unresolved matters.
What CEFR level is "Up in the air"?
This idiom is typically taught at B1 level. It is an intermediate expression that appears frequently in spoken English, everyday conversation, and informal writing.
What are common mistakes with "Up in the air"?
A common mistake is changing the preposition, such as saying 'in the air' or 'up on the air'. The fixed form is always 'up in the air'. For example: The plans are up on the air is incorrect. The correct form is: The plans are up in the air.
What idioms are similar to "Up in the air"?
Similar idioms include: In limbo, On the fence, Hanging in the balance, Touch and go. These share the idea of uncertainty or an outcome that has not yet been decided.
How do I practise idioms like "Up in the air"?
LexFizz's Flash Cards and Flip Tiles exercises are great for practising English idioms. Try writing your own example sentences using the idiom in context, and listen for it in films, podcasts, and conversations.
Can "Up in the air" be used in writing?
Yes. It works well in informal writing, emails, and journalism. Avoid it in formal academic writing unless you are intentionally quoting or discussing the idiom itself. In everyday and business writing it is a natural and clear choice.
Does "Up in the air" have the same meaning in British and American English?
Yes, "Up in the air" is understood in both British and American English with the same meaning: uncertain or not yet decided. The idiom is widely recognised across all major varieties of English.