A prepositional phrase from the words itself "prepositional" and "phrase", it is a phrase that contains a preposition. Obviously, we know what are phrases, so we will deal more with prepositions. Examples of prepositions are: under, between, in, on, above, and many more.
Examples of prepositional phrases are:
1.) under the sea
2.) between the table and chair
3.) in the classroom
4.) on the desk
5.) above him