Indicating the means or method used to achieve something, e.g. transport. She traveled by train to get to the city.
Indicating the agent performing an action. The book was written by the famous author.
Indicating a point in time at which something happens. Please submit your assignment by Friday.
Indicating proximity or nearness. The house is by the river.
Used to separate dimensions when describing area or volume. The room measures 10 feet by 12 feet.
Indicating a rate or amount of change. The population increased by 10% last year.
Indicates the author or creator. The book was written by Platonov.