John was here just now, wasn’t he? vs John wasn’t here just now, was he?

[kohyoongliat]

John was here just now, wasn’t he?
John wasn’t here just now, was he?

Does the first sentence imply that I was quite sure John was here, while the second implies that I was not sure that John was here?

Thanks.

 

[emsr2d2]

John was here just now, wasn’t he?
John wasn’t here just now, was he?

Does the first sentence imply that I was quite sure John was here, while the second implies that I was not sure that John was here?

Thanks.

The first implies that you are fairly sure he was there.
The second is not quite as clear. It might mean you are fairly sure he wasn't there. However, it might also mean that you think he might have been there but you want to check with someone that you're wrong (or right!) In that context, it suggests that you want the answer to be that he wasn't there.

Me: Hi Sarah. I heard a voice I recognised a few minutes ago. John wasn't here, was he?
Sarah: Yes, he was. He just popped in to say hello.
Me: Oh, that's annoying! I owe him £20. If I'd known he was here, I could have given him the money.