If it is not specifically for one person (example, student or OAP card), then yes. However, you can't both use it at the same time. When I lived in London, I had a few PAYG Oyster cards for visitors use.
An ordinary Oyster card, Pay-as-you-go, is transferable. Once you load on a season ticket or other registered user ticket, it isn't.
Not at the same time no.
But on different days, if it's just a "normal" oyster, yes.
You shouldn't. But of course the system doesn't know who's using the card. Certainly you can't both use it at the same time - the second person just won't be let through because the system recognises that the first person has only just used it.
No, you have to have one each, it just covers one person's travel.
Yes but you cannot both use it at the same time.
Absolutely not. They are non-transferrable and if you are stupid enough to try and use it twice at the same time it won't work.
I share mine with my sister. Eitherv of us uses it when one of us goes to London.
That would be fraud and your likely be seen on a security camera
