PII. PRESENTE PERFECTO (PRESENT PERFECT)

 PRESENT PERFECT

1. Estructura

El presente perfecto se forma con:

Sujeto + have / has + participio pasado (V3)

• I / you / we / they → have + V3

• He / she / it → has + V3

Negativa

Sujeto + haven’t / hasn’t + V3

Interrogativa

Have / Has + sujeto + V3?

2. Participio pasado (V3)

• Verbos regulares: -ed
  (worked, visited, cleaned)

• Verbos irregulares: forma V3 específica
  (go → gone, eat → eaten, see → seen, do → done)

3. Usos principales del Present Perfec

A. Experiencias de la vida (sin decir cuándo)

Habla de algo que ha pasado alguna vez, sin tiempo específico.

Ejemplos:

• I have visited a hospital before.

• She has worked with children.

B. Acciones que empezaron en el pasado y continúan

Con for (duración) y since (punto de inicio).

Ejemplos:

• I have worked here for two years.

• He has lived in Mexico since 2020.

C. Acciones recientes con resultado en el presente

Muchas veces con just, already, yet.

Ejemplos:

• The nurse has just arrived.

• The doctor has already reviewed the tests.

• The patient hasn’t eaten yet.

4. Palabras clave

• just (acaba de)

• already (ya)

• yet (todavía, en negativo/preguntas)

• ever / never

• for / since

• recently / lately

5. Diferencia clave: Present Perfect vs. Past Simple

• Present Perfect → sin tiempo específico / conexión al presente

  • I have taken the medicine. (resultado ahora)

• Past Simple → tiempo definido

  • I took the medicine at 8 AM.

6. Ejemplos en contexto médico

• I have checked the patient’s vital signs.

• She has administered three medications today.

• We have worked with premature infants for years.

• The patient has not improved yet.

• Has the doctor seen the X-ray?