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"Llamar por teléfono" is a transitive verb phrase which is often translated as "to phone", and "telefonear" is a transitive verb which is often translated as "to telephone". Learn more about the difference between "llamar por teléfono" and "telefonear" below.
llamar por teléfono(  
yah
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mahr
pohr
teh
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leh
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foh
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noh
)A transitive verb phrase is a phrase that combines a verb with a preposition or other particle and requires a direct object (e.g., take out the trash.).
a. to phone 
La enfermera dijo que me llamarían por teléfono para darme los resultados de la prueba.The nurse said they'd phone me to let me know the test results.
b. to call 
Mi madre vive sola, así que yo la llamo por teléfono todos los días.My mother lives on her own, so I call her everyday.
c. to ring  (United Kingdom)
Regionalism used in the United Kingdom
Ahora voy con mucha prisa, pero luego te llamo por teléfono y hablamos tranquilamente.I'm in a hurry now, but I'll ring you later and we can talk at our leisure.
An intransitive verb phrase is a phrase that combines a verb with a preposition or other particle and does not require a direct object (e.g., Everybody please stand up.).
a. to phone 
Para pedir información no hace falta que vayamos hasta allí, podemos llamar por teléfono.We don't need to go there to make inquiries, we can phone.
b. to call 
¿Ha llamado alguien por teléfono? - Sí, un cliente para hacer un pedido.Has anyone called? - Yes, a client to place an order.
c. to ring  (United Kingdom)
Regionalism used in the United Kingdom
Eva llamó por teléfono para decir que le había surgido algo y no podía comer con nosotras.Eva rang to say that something had come up and she couldn't meet us for lunch.
telefonear(
teh
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leh
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foh
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neh
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ahr
)A transitive verb is a verb that requires a direct object (e.g., I bought a book.).
1. (to call)
a. to telephone 
El médico quedó en telefonearme los resultados cuando los reciba.The doctor said he would phone me the results when he received them.
b. to phone 
Marta se preocupó al telefonear a su hija y que no contestara.Marta got worried when she phoned her daughter and she didn't answer.
An intransitive verb is one that does not require a direct object (e.g., The man sneezed.).
a. to telephone 
El colegio me dijo que podía telefonear para hablar con el profesor de mi hijo.The school told me I could telephone to speak to my son's teacher.
b. to phone 
Para encargar una pizza a domicilio, se puede telefonear o hacer el pedido en línea.To order a pizza delivery, you can phone or order online.