A prepositional phrase acts as either an adjective or an adverb.
Examples:
I made him a taco with lots of cheese. (adjective, describes the taco)
He ate the taco with gusto. (adverb, ate it how)
That book on the desk is due back at the library. (adjective, describes which book)
That book on the desk is due at the library. (adverb, due where)
Yes, a prepositional phrase can act as the subject of a sentence. For example, in the sentence "In the park is where we had a picnic," the prepositional phrase "In the park" serves as the subject.
I'm not sure if your question is whether a prepositional phrase is the same thing as a word group, or if "group" is a prepositional phrase. The answer is no in either case. A word group must express a complete thought. A prepositional phrase is part of a sentence and it has to start with a preposition. "In the group" is a prepositional phrase beginning with the preposition "in."
A prepositional phrase acts like an adjective or adverb in a sentence by providing additional information about the subject or verb.
The prepositional phrase is in the park. Camping is not part of the prepositional phrase.
In the wind is the prepositional phrase.
A prepositional phrase that modifies a noun or pronoun is an adjective prepositional phrase. An adjective prepositional phrase almost always follows the noun/pronoun it modifies.
To is a preposition, but it's not a prepositional phrase unless there is an object of the preposition.
Yes, the phrase from the refrigerator is a prepositional phrase. from is a preposition
with such force is a prepositional phrase.
Yes, in the classroom is a prepositional phrase.
Phrase
Yes, for counting is a prepositional phrase.