ABSTRACT
The simple past tense of strong verbs is indicated by some difference from the present in the vowel of the stem. First, let us note how a typical strong verb is conjugated in the past:
zingen to sing
Present Simple past
ik zing I sing ik zong I sang
jij zingt/zing jij you sing jij zong you sang
hij zingt he sings hij zong he sang
wij zingen we sing wij zongen we sang
jullie zingen you sing jullie zongen you sang
zij zingen they sing zij zongen they sang
The singular of the simple past tense is simply the stem without any ending, the past tense being indicated in this case by the change from i to o.