Learn Dutch: We zullen de buurt herontdekken, mits het weer mooi is. - We will rediscover the neighborhood, provided that the weather is nice.

Dutch allows stacking prefixes! The base verb is dekken (to cover). Adding ont- (which often indicates reversal or deprivation) creates ontdekken (to un-cover, or discover). Finally, adding her- (which means repetition, like 're-' in English) creates herontdekken (to rediscover).

Since herontdekken has two prefixes, is it separable, and how would I form its past participle?

Neither her- nor ont- is separable. Because the verb starts with an inseparable prefix, the prefixes stay firmly attached and the verb doesn't get a ge- in the past participle. If you wanted to say 'We have rediscovered the neighborhood,' it would simply be We hebben de buurt herontdekt.

What exactly does mits mean, and do learners often mix it up with another word?

mits means 'provided that' or 'on the condition that'. English speakers often confuse it with tenzij, which means 'unless'. Use mits for a positive condition (we will do it if the weather is nice) and tenzij for a negative exception (we will do it unless the weather is bad).

Why does the verb is go at the very end of the second half of the sentence?