19. for / since / ago

for與since 比較

for與since可用來表示多久:

Jane is in Ireland. She has been there

for three days.

since Monday.

Richard has been in Canada for six months.

We’ve been waiting for two hours.

I’ve lived in London for a long time.

Richard has been in Canada since January.

We’ve been waiting since 9 o’clock.

I’ve lived in London since I was ten years old.

B. Ago

ago表示 “之前” , “以前” :

Susan started her new job three weeks ago.

‘When did Tom go out?” “Ten minutes ago.’

I had dinner an hour ago.

Life was very different a hundred years ago.

ago與動詞的過去式 (started/ did/had/was等) 連用。

請比較ago與for:

When did Jane arrive in Ireland?

She arrived in Ireland three days ago.

How long has she been in Ireland?

She has been in Ireland for three days.