請教8老師：
1，持有1年有效的2019表申請Waiver，是否從獲批waiver開始2019表就失效了？
-Do you mean your J-1 status is only for one year? If so, you may have no enough time to get J-1 waiver. As far as I know, you need to be J-1 status for at least one year to be qualifed for J-1 waiver based on the Chinese Embassy requirements. So, you had better seek J-1 extension before you apply for J-1 waiver.
還是可以繼續用該2019表待在美國直至過期，同時申請H1簽證或者綠卡？-If your J-1 status is still valid when you get the J-1 waiver, you still can stay in US as a J-1 holder until the J-1 status expires, but you cannot extend your J-1 status after you get J-1 waiver and of course, you can change your status to H-1 or apply for green card.
2，在等待Waiver結果期間能夠回國嗎？-Yes.
3，如果在2019表過期前沒能拿到H1或者綠卡，回國後waiver還有效嗎？-Yes as long as it is approved.
也就是能否回國繼續申請H1或者綠卡？-Yes. But you need to find a job in US for H-1 application.
