Final answer:
The participial phrase in the provided sentence is 'Wearing a big veil and a small bikini,' which functions as an adjective modifying the subject 'the bride.'
Step-by-step explanation:
The participial phrase in the sentence 'Wearing a big veil and a small bikini, the bride shocked the wedding guests' is 'Wearing a big veil and a small bikini'. A participial phrase is a group of words that includes a participle and acts as an adjective; this phrase is modifying the noun 'the bride' by giving more detail about her actions or appearance. Additionally, participial phrases can be moved around within a sentence. For example, the participial phrase could be placed after the noun it modifies without changing the meaning of the sentence much.
In the sentence presented, the participial phrase 'Wearing a big veil and a small bikini', is used to describe the bride's attire, directly modifying the subject 'the bride' and causing the reaction from the wedding guests. This utilization demonstrates the adjective function of the participial phrase. On the contrary, if the participial phrase modifies the verb, as in the example 'The kids went bounding down the stairs,' it is acting adverbially and hence modifies the verb 'went'.