Is time flies formal or informal?

It is neutral and common in speaking and writing.

What is the difference between time flies and time passes quickly?

Time flies is a set phrase. Time passes quickly is a more direct description.

Can I use time flies in IELTS writing?

Yes, but use it only when the tone is natural, not too casual.

Does time flies mean time is short?

No. It means time feels like it moves fast.

← Dictionary

time-flies

/ˈtaɪm flaɪz/

IELTSAcademic

phrase

A reminder that time passes very quickly. People use it when they notice days, months, or years going by faster than expected.

Time flies when you're having fun.
Time flies during exam season.
Time flies, and the kids are grown now.

Adinary Nuance

Use time flies when you mean time seems to pass quickly. It is more natural and fixed than saying time passes quickly in casual speech. It is not the same as flying time, which means the time spent in the air while travelling.

In other languages

Vietnamese: thời gian trôi nhanh
Spanish: el tiempo vuela
Chinese: 时光飞逝
Japanese: 時が経つのが早い
Korean: 시간이 빨리 간다

Etymology

This phrase comes from the old idea that time moves like something flying past. It has been used in English for many centuries as a short reflection on passing time.

Common phrases

time flies byhow time fliestime really flies

Synonyms

time passes quickly the years go by time rushes by

Related words

time fly by pass moment

Frequently asked questions

Is time flies formal or informal?: It is neutral and common in speaking and writing.
What is the difference between time flies and time passes quickly?: Time flies is a set phrase. Time passes quickly is a more direct description.
Can I use time flies in IELTS writing?: Yes, but use it only when the tone is natural, not too casual.
Does time flies mean time is short?: No. It means time feels like it moves fast.