Prepositional phrases, comma boundaries and multiple possession

A prepositional phrase begins with a preposition and includes its object: under the cushion, before sunrise, across the court. It can express place, time, movement, accompaniment or another relationship.

Trap: do not select only the preposition. In “under the old bridge”, the whole phrase is under the old bridge.

When a prepositional phrase comes before the main clause, a comma can make the boundary clear, especially when the phrase is substantial: During the final minutes of the match, the crowd became silent.

Direct IXL evidence in the research supports identifying prepositional phrases, but it did not directly provide a mapped skill for comma placement after them. SkillrHub therefore teaches the comma component as a curriculum extension and avoids claiming direct IXL verification for it.

• one dog → the dog’s collar
• several dogs → the dogs’ leashes
• irregular plural children → the children’s games

Never add an apostrophe just to make a plural: three dogs, not three dog’s.

Sam and Priya’s project can show one jointly owned project. Sam’s and Priya’s projects makes separate ownership clear when each has a different project. Work out the ownership relationship before punctuating.

• preposition alone mistaken for the full phrase
• phrase confused with a dependent clause
• apostrophe added to an ordinary plural
• regular and irregular plural possessives confused
• shared possession and separate possession treated as identical
• comma placed inside rather than after the introductory phrase

IXL directly supports prepositional phrase identification and possessive classification/formation. Direct IXL evidence for the comma-after-prepositional-phrase part of the descriptor was not observed, so that component remains explicitly identified as curriculum-extension teaching.