Unit 18 :
For/ Since / Ago



Since, for and ago: talking about periods of time

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for & since

Jack is in Brazil. He has been there for three days/ since Monday.

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> ago = before now (現在之前)

  1. Benny started his new job three days ago. (= three days before now.)
  2. “When did Betty leave?” “Twenty minutes ago.” (= twenty minutes before now.)
  3. I had lunch an hour ago.
  4. Life is very different a hundred years ago.

> ago = use in past tense (started/did/had/was …)

* Compare with “ago” and “for”:

1) When did Albert arrive in London?

    He arrived in London three days ago.

2) How long has he been in London?

    He has been in London for three days.