Do you remember how we form the past tense for modal verbs?
Yes, I do! We use the Präteritum, right?
Exactly. And the conjugation?
Well, the modal verb is conjugated in Präteritum and then we just add an infinitive verb at the end of the sentence.
Ich kann es nicht glauben! I can't believe it!
You mean: Ich konnte es nicht glauben?
Hahaha, well done! Have you noticed something about the Präteritum conjugation of these verbs? Let's look at können more closely: