This is a test of commonsense. Complete the next sentence:

How to repair vertical blinds
Adjust blinds that won't turn.
If your blinds aren't closing, or if one or two won't close, this is usually a simple fix. Check each blind individually.
It's likely one or two blinds are backwards and simply need to be twisted into the right position. Blinds may also be overlapping, in which case you can use your hands to gently push them apart.