Ages ago vs That was a long time ago

When to use each in English, with meaning, register, and examples.

Ages ago

InformalTop 2,000 (common)

That was a long time ago

Top 2,000 (common)
Most formal: That was a long time ago
 Ages agoThat was a long time ago
Pronunciation🇬🇧 //ˈeɪdʒɪz əˈɡəʊ//🇺🇸 //ˈeɪdʒɪz əˈɡoʊ//🇬🇧 //ðæt wəz ə lɔŋ taɪm əˈgoʊ//🇺🇸 //ðæt wəz ə lɔŋ taɪm əˈgoʊ//
MeaningA long time in the pastIt happened a long time in the past.
ExampleWe visited that place ages ago.That was a long time ago when we went camping together.
RegisterInformalNeutral
How commonTop 2,000 (common)Top 2,000 (common)
Collocationsremember ages ago, talk about ages ago, think back ages ago, come across ages ago, met ages agohappened a long time ago, forgotten a long time ago, placed a long time ago
Common mistakesUsing 'age' instead of 'ages' for plural context., Not using it in appropriate casual situations., Confusing it with 'ages' meaning just a long time without the 'ago'.Using 'ago' incorrectly with future events., Confusing 'long time ago' with 'a long time'., Not using it to specify a past event.
Usage notesUsed in casual conversation to refer to a significant period of time that has passed. More appropriate in everyday speech than in formal writing.Use this phrase to refer to events from the distant past. It's commonly used in conversation but can also appear in writing. Avoid it in formal reports.

See it in real clips

Ages ago
That was a long time ago

Frequently asked questions: Ages ago vs That was a long time ago

What's the difference between Ages ago and That was a long time ago?

Ages ago: A long time in the past That was a long time ago: It happened a long time in the past.

Which is more formal: Ages ago and That was a long time ago?

That was a long time ago is the most formal of these.

Can you show an example of each?

Ages ago: We visited that place ages ago. That was a long time ago: That was a long time ago when we went camping together.

Can I use Ages ago and That was a long time ago interchangeably?

Not always. Ages ago and That was a long time ago are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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