Sam was here at ten o'clock.肯定回答,否定回答

问题描述:

Sam was here at ten o'clock.
肯定回答,否定回答

什么意思?

山姆10点钟的时候在这里,但现在不在

Sam was here at ten o'clock
Sam wasn't here at ten o'clock
Was Sam here at ten o'clock?