Final answer:
The sentence can be reordered as "Am Mittwoch will mein Vater in die Stadt gehen."
Step-by-step explanation:
The sentence "Mein Vater will am Mittwoch in die Stadt gehen" can be reordered as "Am Mittwoch will mein Vater in die Stadt gehen." In German, the time usually comes before the subject, so by moving "am Mittwoch" to the beginning of the sentence, we achieve the correct word order.
Learn more about Sentence structure in German