TKG English Learner's Dictionary

ago

agoadverb

American /əˈɡoʊ/ British /əˈɡəʊ/
not gradable
very commondefining vocabulary

  1. before now, by the length of time stated

    Ago comes after the length of time (two days ago, a long time ago) and measures back from the present moment. It goes with the simple past, not the present perfect: We moved here three years ago. To measure back from a time in the past, use before or earlier: I had met her two years before.

    not gradable [not gradable]

    Collocations

    phrase a long time ago, long ago, not long ago, a while ago, a few minutes ago, ages ago

    Compare before (before or earlier counts back from a time in the past, not from now: I had met her two years before); since (since gives the starting point; ago gives the distance back: since Monday, three days ago); for (for gives the length of a period: for three days)

Usage

Ago is never used on its own or before the time phrase: two days ago, not ago two days. A long time ago and long ago mean the same; long ago is more literary.

Common mistakes

I came here before two days. I came here two days ago.
Ago, not before, counts back from now, and it comes after the time phrase.
I have lived here since three years ago. I have lived here for three years.
Since takes a starting point (since Monday) and for takes a length (for three years); ago is not used after since.
I have seen him two days ago. I saw him two days ago.
Ago fixes a finished time in the past, so the verb is the simple past, not the present perfect.

Word origin

Ago is a short form of agone, the past participle of an old verb meaning to go by or pass away. Two days ago was two days gone, which is why ago comes after the time phrase, like a participle.

Checked against: Wiktionary, Online Etymology Dictionary (2026-09-16)

For translators

Meaning across languages Ago measures back from the moment of speaking. Counting back from a time in the past uses before or earlier: I had seen him two days before.
Grammar trap Ago follows the time phrase and points back from now; it takes the simple past, not the present perfect: she left two hours ago. Many languages put the equivalent word before the time phrase or use a preposition; the English order is fixed.
Pronunciation trap Two syllables with the stress on the second: uh-GO. The first is the weak uh sound, as at the start of about.