Answer:
1. Please place the keys on the table. - (prepositional) phrase
2. They decided to watch a movie. - not a phrase (clause)
3. The glasses are on the shelf. - (prepositional) phrase
4. Enrique became excited when he heard the news. - not a phrase (clause)
5. Jimmy, fearing a low score, studied diligently for his exam. - (prepositional) phrase
6. In 1934, my grandfather came to the United States. - (prepositional) phrase
7. The clothes in the corner should be donated to charity. - (prepositional) phrase
8. Casper, a master of the violin, is learning to play the guitar. - not a phrase (clause)
9. To repair a car, you need to have tools and experience. - not a phrase (clause)
10. Before she left home, Helena ate breakfast and read a magazine. - (prepositional) phrase
Explanation:
You haven't pointed out which words are underlined, but I found a similar question online and underlined them for you.
A phrase is a group of words with a certain meaning. A group of words that consists of a preposition, its object, and words that modify the object is called a prepositional phrase.
A clause is a group of words that represents a unit smaller than the sentence. It must contain a verb (predicate), but it usually contains a subject, as well. Some clauses can stand alone as sentences (independent clauses), while some can't (dependent clauses) as they don't express a complete thought.