should, ought to
This structure indicates a strong expectation or assumption, expressed politely.
Exemples
お客様は元気なはずです。
The guest should be healthy.
明日、医者が来るはずです。
The doctor should come tomorrow.
この薬は効くはずです。
This medicine should work.
Vérification rapide
Ce médicament devrait fonctionner___.