Presente Simple

1. Se usa el presente perfecto para describir una experiencia. No lo usamos para acciones especificas.
* Ejemplos:
* I have never flown in a plane.
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I have never flown in aplane. (Nunca he volado en un avión.)
* He has worked in many different museums.
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He has worked in many different museums. (Ha trabajado en muchos museos diferentes.)
* We have been toRio de Janiero.
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We have been to Rio de Janiero. (Hemos ido a Rio de Janiero.)
2. Se utiliza el presente perfecto para un cambio en el tiempo.
* Ejemplos:
* I have become moretimid in my old age.
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I have become more timid in my old age. (Me he vuelto más tímido en mi vejez.)
* Their English has improved a lot this year.
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Their English has improved a lotthis year. (Su inglés ha mejorado mucho este año.)
* He has learned to be more patient.
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He has learned to be more patient. (Ha aprendido a ser más paciente.)
3. Se usa para lasexitosos.
* Ejemplos:
* Our football team has won the championship three times.
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Our football team has won the championship three times. (Nuestro equipo de fútbol ha ganado elcampeonato tres veces.)
* Dan has finished writing his first novel.
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Dan has finished writing his first novel. (Dan ha terminado de escribir su primera novela.)
* Scientists have succeededin curing many illnesses.
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Scientists have succeeded in curing many illnesses. (Los científicos han tenido éxito en la curación de muchas enfermedades.)
4. Usamos el presente perfecto paraacciones que todavía no han pasado. El uso del presente perfecto en estos casos indica que aún estamos esperando la acción, por eso, frecuentemente usamos los adverbios "yet" y "still".
*Ejemplos:
* The plane hasn't arrived yet.
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The plane hasn't arrived yet. (El avión no ha llegado todavía.)
* Our team still hasn't won a championship.
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Our team still hasn't won...