Prepositions create difficulties for English language learners. To master their usage, close attention must be paid to spoken and written language. Keeping a dictionary handy is advised. Prepositions link nouns, pronouns, and phrases to other words. A prepositional phrase begins with a preposition and ends with a noun, pronoun, gerund, or clause. Prepositional phrases mostly function as adjectives or adverbs by providing more information about nouns or verbs. The document then examines different prepositional phrases using "at".