The standard sentence format in English presents the subject before the verb. In reversed sentences, you need to find the subject and then make sure it matches the verb. To find the subject, fill the following blank with the verb and then ask the question of yourself: who or what _____?
Subject comes after the verb
Throughout Brown Cave National Park, there are passages which run over 500 kilometers.
Who or what runs? The passages do. Even though you might be tempted to think 'Brown Cave National Park' is the subject, it is not doing the action of the verb. Since 'passages'is plural, it must match up to a plural verb.
