Final answer:
The phrase 'In spite of his good grades' is a prepositional phrase, not a clause, as it lacks a subject and verb and provides contrasting context in a sentence.
Step-by-step explanation:
The phrase 'In spite of his good grades' acts as a prepositional phrase and not a full clause. A clause typically contains a subject and verb, while a phrase is a group of words that does not contain a subject-doing-verb component. In this instance, 'In spite of his good grades' provides a contrast or concession but lacks a subject and a verb, which is why it is considered a phrase.
Prepositional phrases like this are used in sentences to indicate relationships between different elements and can provide context or additional details. For example, the phrase could lead into a sentence that explains a contrasting situation such as 'In spite of his good grades, he still struggled with confidence.'