Past continuous
Rule: was/were + infinitive (without to) + -ING
For example: I was looking at... = ik was aan het kijken naar...

Past tense
Rule: infinitive (without to) + -ED
For example: I looked at him. = Ik keek naar hem.
BUT some verbs don't follow the rule for the past tense.
For example: to see => I saw it on the internet. = Ik zag het
op het internet.