We ate dinner at seven o’clock last night.

[Alice Chu]

Please tell me if my understanding is correct.
1) We ate dinner at seven o’clock last night.
→ It means “eating” started at seven o’clock last night

2) We were eating dinner at eight o’clock last night.
→ It means “eating” was in progress at eight o’clock last night

3) We had eaten dinner by nine o’clock last night.
→ It means “eating” was completed at some point before nine o’clock last night.
We cannot replace "by" with "at" here because the past perfect can’t be used with a specific time.

 

[probus]

In 3, by is usual, but I wouldn't go do far as to say at is wrong. Others may disagree, and it is admittedly hard to think of a context in which one would use at.

 

[5jj]

past perfect can’t be used with a specific time.

It can in the right context.

 

[emsr2d2]

It can in the right context.

Absolutely!

We were really organised yesterday. We'd done all the housework by eleven, [we'd] made lunch for fifteen people by two, and [we'd] packed everything we need for our holiday by six. As a result, we had a lovely chilled evening with Netflix and a takeaway. We're setting off for Cornwall in about fifteen minutes.

 

[jutfrank]

Please tell me if my understanding is correct.
1) We ate dinner at seven o’clock last night.
→ It means “eating” started at seven o’clock last night

I don't think it's right to say it means that.

2) We were eating dinner at eight o’clock last night.
→ It means “eating” was in progress at eight o’clock last night

Yes, that's right.

We cannot replace "by" with "at" here because the past perfect can’t be used with a specific time.

Neither statement here is right.

 

[Tdol]

Absolutely!

We were really organised yesterday. We'd done all the housework by eleven, [we'd] made lunch for fifteen people by two, and [we'd] packed everything we need for our holiday by six. As a result, we had a lovely chilled evening with Netflix and a takeaway. We're setting off for Cornwall in about fifteen minutes.

Wow, and you even made time for Netflix. I've got some washing-up in the sink you may want to do. :-D

 

[emsr2d2]

Wow, and you even made time for Netflix. I've got some washing-up in the sink you may want to do. :-D

There's always time for Netflix! And, in my case, for washing up. I regularly offer to wash up at other people's houses. It is the ONLY type of housework I enjoy, and I really enjoy it!