Questions & Answers about Toen ik zo'n bizar ongeluk zag, was ik bang.
Why do we use zo'n here instead of zulke?
Zo'n means "such a" and is used for singular countable nouns like ongeluk (accident). You would use zulke if the noun were plural (such accidents) or uncountable.
Why doesn't the adjective bizar get an -e ending here?
Ongeluk is a het-word. When a het-word follows an indefinite word like een or zo'n (which is actually a contraction of zo een), the adjective before the noun does not get an -e ending.
Can I use wanneer instead of toen for "when" in this sentence?
No, you must use toen. In Dutch, toen is strictly used for a single, specific event in the past. Wanneer is used for questions, present/future events, or repeated past events (meaning "whenever").
Why is the verb zag at the very end of the first clause?
The word toen (when) introduces a subordinate clause. In Dutch subordinate clauses, the verb is pushed all the way to the end.
Why does the second part say was ik instead of ?