Swedish

Strong verbs are cool.

All verbs would take -en with I: I ären, I voren, I haden varit, I skolen vara, I måsten, I tror
In the present, plurals are like the infinitive, except vi äro: vi hafva
In the past, weak verbs had one form, while strong plurals would take -o, some with a different stem vowel (det fanns, de funnos) shared by the subjunctive.
1st. pl. imperative with -om: låtom oss tro
2nd pl. imperative with n: tron
vara form perfect past with intransitive verbs: jag är uppstigen
present subjunctive replaces infinitive’s a with -e (if not -a, same as infinitive)
past subjunctive only exists with strong verbs, adding -e (to plural past stem)

Note verbs themselves were often spelled differently: hafva, blifva, skrifva etc.