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• Preposición que expresa el agente de una acción, el modo o medio, la proximidad a algo, una fecha límite, el medio de transporte o comunicación, la magnitud de una diferencia o la autoría de una obra.

A preposition indicating agency or means of action, proximity or location beside something, a deadline or time limit, method of transport or communication, measurement of difference, or authorship and creation.

1. Agency or means of an actionA2formal

   Used to indicate the person, thing, or force that performs an action, or the method, instrument, or process by which something is done or achieved.

   Agente o medio de una acción

   • The book was written by Tolstoy.
   • The room was lit by candlelight.
   • She traveled by train.
   • You can pay by credit card.

2. Proximity or position next to somethingA2formal

   Indicates that someone or something is located near, beside, or at the side of a place, object, or person.

   Cerca de / Al lado de

   • She sat by the window.
   • There's a café by the station.
   • He stood by the door waiting.
   • We live by the sea.

3. Deadline or latest time for somethingA2formal

   Used to indicate the latest time or date by which an action must be completed or an event must occur; not later than.

   fecha límite

   • Please submit the report by Friday.
   • We need to leave by 6 o'clock.
   • The project must be finished by next month.
   • Reply by email by the end of the day.

4. Method of transport or communicationA1formal

   Used to specify the vehicle, system, or medium used for traveling, sending, or transmitting something.

   Medio de transporte o comunicación

   • We went by car.
   • Send the document by post.
   • She contacted me by phone.
   • They traveled by plane.

5. Measurement of difference or rateB1formalbusiness

   Used to indicate the amount of change, difference, or margin between two values, or to express a rate, unit, or standard of measurement.

   Por (diferencia o tasa)

   • Prices increased by 10 percent.
   • She won by a narrow margin.
   • Rent is charged by the square meter.
   • The temperature dropped by five degrees.

6. Authorship, creation, or originB1formalart

   Used to attribute a work, invention, artwork, or creation to the person or entity responsible for producing it.

   Autoría, creación u origen

   • A painting by Van Gogh.
   • A song by The Beatles.
   • This theory was developed by Einstein.
   • The building was designed by a famous architect.