Prepositional phrases begin with a preposition - a word that usually starts a phrase describing the relationship between a subject and the object of the phrase. Prepositions are words such as above, below, in, on, and so forth. Prepositional phrases are phrases like "around the corner", "under the bed", "near the third house" "on the left". In the last example, two prepositional phrases could follow each other to extend the description of proximity. In traditional English grammatical construction, sentences should not end with a prepositional phrase; ie "The pot on the stove is red" in preference to "The red pot is on the stove."
A preposition is a word that shows location, such as in, on, under, at, and besides. These little words occur in many different sentences and can be very confusing to English language learners.
A prepositional phrase is a longer group of words that uses a preposition along with a noun or pronoun to give a better description. The phrase functions as a single entity and does not contain a subject and a verb.
Prepositional phrases can be located in the beginning, middle or end of a sentence.
The boy sat besides the swimming pool dreaming of the girl in his 6th period class. To identify the preposition, ask yourself where the boy sat. Obviously, the answer is besides the swimming pool. Notice that besides the swimming pool is not a complete thought; therefore, it is a phrase. The word besides shows location and makes the phrase a prepositional phrase.
Sometimes, a prepositional phrase may occur at the beginning of a sentence.
In the middle of his presentation, Steven realized that he had forgotten to turn off his stove.
Alternatively, the sentence can be rearranged and the prepositional phrase can be placed at the end.
Brian picked up his backpack and stormed out of the door.