Hello Houtiedienn43
You can scan your SwissPass at the ticketing machine. Underneath the screen, there is a scanner. Or, you connect with swisspass.ch and you will see the expiry date in your customer account.
https://sbb-tickets.cc/en/help-and-contact/my-travelcards/overview-of-my-travelcards.html
If your Half Fare Card expires, the TNW Abo is still valid. These are two indepedent products, there is no half fare discount for abonnements; thus, an active Half Fare Card is not required to continue using the TNW Abo.
Kind regards,
Roland