Learn Dutch: Wij verhuisden vorige week naar de stad.

You have to look at the full infinitive verb: verhuizen. The letter before the -en is z. Because z is a voiced sound (it is not in 't kofschip), the past tense gets -den. Dutch spelling rules do not allow a syllable to end in z, so it changes to s in the past tense spelling, but it keeps the d from the original z.

Why is vorige week in the middle of the sentence instead of at the end?

In Dutch, time expressions usually come before place expressions. This is often called the Time-Manner-Place rule. Therefore, the time (vorige week) must come before the destination (naar de stad).

Why is there an -e on the end of vorige?

Week is a de-word (de week). When an adjective comes directly before a noun that uses de, the adjective gets an extra -e at the end.

Why do we use naar for "to" here?

Naar is the standard preposition used for physical movement or direction towards a destination, such as a city, country, or building.