Breakdown of We zijn wezen hardlopen en daarna zijn we wezen picknicken.
zijn
to be
en
and
daarna
after that
we
we (unstressed form of wij)
Questions & Answers about We zijn wezen hardlopen en daarna zijn we wezen picknicken.
Why does this sentence use wezen instead of geweest?
This is the action perfect structure. When you say you went out to do an activity in the past, you use a form of zijn plus the infinitive wezen, followed by the activity verb. You only use geweest if there is no other verb involved, like in We zijn in het bos geweest (We have been in the forest).
Why is the word order zijn we in the second half, rather than we zijn?
This is because of the word daarna (after that). In Dutch, the conjugated verb must be the second element in a main clause. Since the second clause starts with daarna, the verb zijn must come right after it, pushing the subject we to the third position.
Why are hardlopen and picknicken used in their full infinitive forms here?
The zijn wezen construction always pairs with a bare infinitive. You simply use the whole dictionary form of the action verb exactly as it is, without changing it to a past participle or adding te in front of it.
Could I just say We gingen hardlopen en daarna gingen we picknicken instead?
Yes, that is grammatically correct and means almost the same thing. However, the zijn wezen structure is extremely common in spoken Dutch. It specifically emphasizes that you went out, completed the activity, and have now returned.